2014
All events, 2014
From Sensory Neural Codes to Behavior
Lecture
Wednesday, March 5, 2014
Hour: 14:30
Location:
Gerhard M.J. Schmidt Lecture Hall
From Sensory Neural Codes to Behavior
Dr. Moshe Parnas
Centre for Neural Circuits and Behaviour
University of Oxford
Most neurons involved in perceptual judgments are at least two synapses removed from sensory receptors. Psychophysical models that link perception to the physical qualities of external stimuli are thus black boxes. Opening these black boxes is challenging and requires comprehensive estimates of activity in many neurons carrying perceptually relevant signals. Because sensory representations are distributed over large numbers of neurons, such estimates have generally remained elusive. Here, we take advantage of the well-characterized olfactory system of fruit flies to relate knowledge of the neuronal population representations of odors to behavioral measures of odor discrimination. Flies detect odors using ~50 types of olfactory receptor neurons (ORNs). ORN axons segregate anatomically by receptor type and transmit signals via separate synaptic relays, to discrete classes of excitatory projection neurons (ePNs). Previously, ORN responses to odors and a transformation estimating PN spike rates from measured ORN spike rates were presented. ePNs project to the mushroom body, and the lateral horn (LH). The LH, thought to be responsible of naïve behavior, also receives input from a functionally uncharacterized group of GABAergic inhibitory PNs (iPNs). The fact that iPNs target exclusively the LH hints at a possible function of these inhibitory neurons in naïve behavior. We formulate and test a simple model of innate odor discrimination that takes as its input the estimated PN signals projected onto the LH and generates as its output a prediction of whether two odors can be distinguished. We show that the main determinant of discriminability is the distance between the PN activity patterns evoked by two odors. Experimental manipulations of this distance have graded predictable perceptual consequences. We further show that, inhibition by iPNs makes closely related odors easier to distinguish, in all likelihood by imposing a high-pass filter on ePN output that stretches the distances between partially overlapping odor representations.
Decoding Consciousness
Lecture
Tuesday, February 25, 2014
Hour: 12:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Decoding Consciousness
Prof. Geraint Rees
Institute of Cognitive Neuroscience, University College London (UCL)
Electrophysiological signatures of consciousness
Lecture
Tuesday, February 18, 2014
Hour: 12:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Electrophysiological signatures of consciousness
Prof. Stanislas Dehaene
College de France and INSERM-CEA Cognitive Neuroimaging Unit
Mapping Neuroplasticity Underlying Addictive Behavior
Lecture
Sunday, February 16, 2014
Hour: 10:30
Location:
Arthur and Rochelle Belfer Building for Biomedical Research
Mapping Neuroplasticity Underlying Addictive Behavior
Dr. Yonatan (Yoni) Kupchik
Dept of Neurosciences, Medical University of South Carolina,Charleston, South Carolina, USA.
Understanding the neural circuitry underlying addictive behavior is essential as a first step towards treating addiction. The nucleus accumbens and the ventral pallidum are two interconnected regions known to mediate reward-related behavior. Using a multidisciplinary approach I describe synaptic changes in both regions following exposure to cocaine. However, the connectivity patterns between these regions and how specific projections are affected by drugs of abuse remain elusive. In an attempt to elucidate the nature of these connections I will show preliminary results calling for a re-examination of the current thinking about accumbal inputs to the ventral pallidum. Future work will engage in describing how these pathways are differentially changed in drug addiction.
Acute and chronic effects of oxytocin on emotinality and on the consequences of chronic psychosocial stress
Lecture
Thursday, February 13, 2014
Hour: 10:00
Location:
Camelia Botnar Building
Acute and chronic effects of oxytocin on emotinality and on the consequences of chronic psychosocial stress
Prof. Dr. Inga D. Neumann
Dept of Behavioural and Molecular Neuroendocrinology
Regensburg University
Brain oxytocin has been repeatedly shown to exert anxiolytic effects and to inhibit the activity of the HPA axis. These acute effects are mediated via activation of hypothalamic oxytocin receptors, which are GPCR, and subsequently of the MAPK pathway. In order to establish oxytocin as a potential psychotherapeutic option, effects of chronic neuropeptide treatment need to be studied. Chronic intracerebral infusion of oxytocin over 2 weeks dose-dependently increased anxiety-related behaviour and reduced oxytocin receptor binding within relevant brain regions. Thus, before oxytocin can be considered a therapeutic option to treat patients suffering from, for example, autism, schizophrenia, social phobia or drug addiction, thorough investigations are needed to reveal alterations of the endogenous oxytocin system. However, application of the low dose of oxytocin to male mice during 3-weeks exposure to an established chronic psychosocial stress paradigm - the chronic subordinate colony housing - attenuated the adverse chronic stress effects on immunological, physiological and emotional parameters further supporting ist stress-protective properties.
http://www.uni-regensburg.de/biologie-vorklinische-medizin/neurobiologie-tierphysiologie/team-mitarbeiter/prof-dr-inga-d-neumann/index.html
The match/mismatch hypothesis: Are physiological alterations following stress exposure adaptive?
Lecture
Wednesday, February 12, 2014
Hour: 12:30
Location:
Gerhard M.J. Schmidt Lecture Hall
The match/mismatch hypothesis: Are physiological alterations following stress exposure adaptive?
Dr. Mathias V. Schmidt
Max Planck Institute of Psychiatry, Munich, Germany
Chronic stress is widely regarded as key risk factor for a variety of diseases, including depression. Yet, while some individuals are vulnerable to stress, others are remarkably resilient. It seems clear that genetic predispositions interact with environmental demands such as chronic stress and modulate its long-term outcome. In addition, there is abundant evidence that environmental circumstances early in life are capable of shaping the adult phenotype. In the last years two seemingly opposing views on early life stress have emerged, the two-hit model and the mismatch model. While the first hypothesis states that aversive experiences early in life predispose individuals to be more vulnerable to aversive challenges later in life, the second hypothesis argues that aversive experiences early in life result in individuals that are better adapted to aversive challenges later in life. There are published data that support either hypotheses, but the interaction with genetic predispositions has rarely been addressed. In my presentation I will propose that both views may be accurate and that the outcome of an early-life stress exposure depend on the genetic background of the individual. In addition, even within the same individual certain phenotypes may be progressively affected by multiple stress exposures (two-hit model), while other phenotypes would be most affected under mismatched conditions. I will illustrate the potential of genetic variations to modulate the outcome of early life adversity and discuss research strategies necessary to address the issue of genetic*development*environment interaction.
Insect inspired robotics:from unmanned micro-aerial-vehicles to the Mars explorer
Lecture
Tuesday, February 11, 2014
Hour: 12:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Insect inspired robotics:from unmanned micro-aerial-vehicles to the Mars explorer
Prof. Amir Ayali
Dept of Zoology, Faculty of Life Sciences Tel Aviv University
Insects are an inexhaustible source for scientists who desire to inspire ideas, processes, structures and functions from biology and implement them into engineering, specifically those interested in locomotion and in the improvement of robot mobility. Novel insights are offered based on a collaborative and combined approach that includes high-speed video monitoring of behavior, electrophysiological recordings of nerves and muscles activity, mathematical modeling and computer simulations. An overview will be presented of several different research projects focusing on cockroach running, caterpillar crawling (soft robotics), locust jumping, flight (remote control), and swarming.
Resolution of Ambiguity:Clues to the Mechanisms of Reading
Lecture
Tuesday, February 4, 2014
Hour: 12:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Resolution of Ambiguity:Clues to the Mechanisms of Reading
Prof. Zohar Eviatar
Dept of Psychology and the Institute of Information Processing and Decision Making (IIPDM)
University of Haifa
The human race has been reading and writing for only 5,000 years, suggesting that the mechanisms for these processes involve both cultural evolution and biological exaptation. Brain mechanisms of reading are hard to discern because skilled reading is so fast and efficient. Use of ambiguous words allows us to slow down some of these processes and explore the interactions of orthographic, phonological, and semantic processes. We took advantage of the characteristics of Hebrew to explore the relative effects of phonological and semantic ambiguity on access to meaning. Twenty-three participants performed a semantic decision talk on pairs of words. Half the pairs were constituted of two unambiguous words, and in half, the first word was either a homophonic homograph (like bank), or a heterophonic homograph (like tear). Our procedure allowed us to separately examine two stages of the access to meaning: the activation of multiple meanings, and then the selection of the appropriate meaning. Previous imaging studies of ambiguity resolution have not made this distinction. In the first stage, we show that different regions of the left hemisphere respond differentially to homophones and to heterophones in both whole brain analysis and in ROI comparisons of sub-regions of both anterior and posterior regions of the left hemisphere. In the second stage, in meaning selection, we again see different effects that are dependent of the phonological status of the ambiguous word, and also similar effects of the interaction between frequency effects and contextual effects in the two hemispheres. We interpret these findings in the context of a brain model of reading.
Mechanisms of local circuit dynamics in freely moving animals
Lecture
Monday, January 27, 2014
Hour: 12:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Mechanisms of local circuit dynamics in freely moving animals
Dr. Eran Stark
NYU Neuroscience Institute
Langone Medical Center New York University
Much of what we know about how neurons interact and form ensemble activity patterns comes from recordings in cell cultures, brain slices, and anesthetized animals, yet dynamics in the intact brain of a behaving animal might differ. I will describe an approach to the study of local circuit dynamics in freely-moving animals, namely the combination of high-density extracellular recordings coupled with multi-site/multi-color optogenetic stimulation, combined with in-vivo pharmacology. This approach, applied to the rodent neocortex and hippocampus, yielded surprising insight into mechanisms of multiple phenomena, including spiking regime resonance, the generation of high-frequency oscillations, and spike phase precession.
Mechanisms of vocal learning in songbirds and humans
Lecture
Monday, January 20, 2014
Hour: 14:30
Location:
Wolfson Building for Biological Research
Mechanisms of vocal learning in songbirds and humans
Dr. Dina Lipkind
Hunter College
The City University of New York
Songbirds are a great model for studying how the brain solves the challenges of vocal imitation, since, like human infants, young songbirds learn to produce complex vocal sequences that are exact copies of those of adult conspecifics. This feat is thought to be accomplished by matching the bird's motor performance to a memorized sensory template. To study this process experimentally, we use a computer interface that presents birds with specific vocal imitation tasks and records their entire vocal output during the process.
Applying this methodology to vocal combinatorial learning, we trained juvenile zebra finches to swap syllable order in their song, or insert a new syllable into a string. Surprisingly, solving these tasks required a prolonged stage of learning new transitions between syllables one by one, indicating that the ability to rearrange vocal sounds is not the starting point of vocal learning, but a laboriously achieved endpoint. Analysis of babbling development data of human infants revealed that infants face a similar challenge in acquiring new transitions between syllables, suggesting that birds and humans share a common developmental stage of gradually learning to combine sounds into sequences.
In a current set of experiments, I am testing hypotheses about the computations involved in sensori-motor vocal learning. For example, is the motor output matched to the sensory template as a single unit, or is the match computed independently for different levels of the song hierarchy? Preliminary results suggest that matching vocal performance to the template occurs independently on at least two levels: the level of individual syllables, and the level of syllable sequences, suggesting that learning on these levels is carried out by distinct neural mechanisms.
Pages
2014
All events, 2014
From Sensory Neural Codes to Behavior
Lecture
Wednesday, March 5, 2014
Hour: 14:30
Location:
Gerhard M.J. Schmidt Lecture Hall
From Sensory Neural Codes to Behavior
Dr. Moshe Parnas
Centre for Neural Circuits and Behaviour
University of Oxford
Most neurons involved in perceptual judgments are at least two synapses removed from sensory receptors. Psychophysical models that link perception to the physical qualities of external stimuli are thus black boxes. Opening these black boxes is challenging and requires comprehensive estimates of activity in many neurons carrying perceptually relevant signals. Because sensory representations are distributed over large numbers of neurons, such estimates have generally remained elusive. Here, we take advantage of the well-characterized olfactory system of fruit flies to relate knowledge of the neuronal population representations of odors to behavioral measures of odor discrimination. Flies detect odors using ~50 types of olfactory receptor neurons (ORNs). ORN axons segregate anatomically by receptor type and transmit signals via separate synaptic relays, to discrete classes of excitatory projection neurons (ePNs). Previously, ORN responses to odors and a transformation estimating PN spike rates from measured ORN spike rates were presented. ePNs project to the mushroom body, and the lateral horn (LH). The LH, thought to be responsible of naïve behavior, also receives input from a functionally uncharacterized group of GABAergic inhibitory PNs (iPNs). The fact that iPNs target exclusively the LH hints at a possible function of these inhibitory neurons in naïve behavior. We formulate and test a simple model of innate odor discrimination that takes as its input the estimated PN signals projected onto the LH and generates as its output a prediction of whether two odors can be distinguished. We show that the main determinant of discriminability is the distance between the PN activity patterns evoked by two odors. Experimental manipulations of this distance have graded predictable perceptual consequences. We further show that, inhibition by iPNs makes closely related odors easier to distinguish, in all likelihood by imposing a high-pass filter on ePN output that stretches the distances between partially overlapping odor representations.
Decoding Consciousness
Lecture
Tuesday, February 25, 2014
Hour: 12:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Decoding Consciousness
Prof. Geraint Rees
Institute of Cognitive Neuroscience, University College London (UCL)
Electrophysiological signatures of consciousness
Lecture
Tuesday, February 18, 2014
Hour: 12:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Electrophysiological signatures of consciousness
Prof. Stanislas Dehaene
College de France and INSERM-CEA Cognitive Neuroimaging Unit
Mapping Neuroplasticity Underlying Addictive Behavior
Lecture
Sunday, February 16, 2014
Hour: 10:30
Location:
Arthur and Rochelle Belfer Building for Biomedical Research
Mapping Neuroplasticity Underlying Addictive Behavior
Dr. Yonatan (Yoni) Kupchik
Dept of Neurosciences, Medical University of South Carolina,Charleston, South Carolina, USA.
Understanding the neural circuitry underlying addictive behavior is essential as a first step towards treating addiction. The nucleus accumbens and the ventral pallidum are two interconnected regions known to mediate reward-related behavior. Using a multidisciplinary approach I describe synaptic changes in both regions following exposure to cocaine. However, the connectivity patterns between these regions and how specific projections are affected by drugs of abuse remain elusive. In an attempt to elucidate the nature of these connections I will show preliminary results calling for a re-examination of the current thinking about accumbal inputs to the ventral pallidum. Future work will engage in describing how these pathways are differentially changed in drug addiction.
Acute and chronic effects of oxytocin on emotinality and on the consequences of chronic psychosocial stress
Lecture
Thursday, February 13, 2014
Hour: 10:00
Location:
Camelia Botnar Building
Acute and chronic effects of oxytocin on emotinality and on the consequences of chronic psychosocial stress
Prof. Dr. Inga D. Neumann
Dept of Behavioural and Molecular Neuroendocrinology
Regensburg University
Brain oxytocin has been repeatedly shown to exert anxiolytic effects and to inhibit the activity of the HPA axis. These acute effects are mediated via activation of hypothalamic oxytocin receptors, which are GPCR, and subsequently of the MAPK pathway. In order to establish oxytocin as a potential psychotherapeutic option, effects of chronic neuropeptide treatment need to be studied. Chronic intracerebral infusion of oxytocin over 2 weeks dose-dependently increased anxiety-related behaviour and reduced oxytocin receptor binding within relevant brain regions. Thus, before oxytocin can be considered a therapeutic option to treat patients suffering from, for example, autism, schizophrenia, social phobia or drug addiction, thorough investigations are needed to reveal alterations of the endogenous oxytocin system. However, application of the low dose of oxytocin to male mice during 3-weeks exposure to an established chronic psychosocial stress paradigm - the chronic subordinate colony housing - attenuated the adverse chronic stress effects on immunological, physiological and emotional parameters further supporting ist stress-protective properties.
http://www.uni-regensburg.de/biologie-vorklinische-medizin/neurobiologie-tierphysiologie/team-mitarbeiter/prof-dr-inga-d-neumann/index.html
The match/mismatch hypothesis: Are physiological alterations following stress exposure adaptive?
Lecture
Wednesday, February 12, 2014
Hour: 12:30
Location:
Gerhard M.J. Schmidt Lecture Hall
The match/mismatch hypothesis: Are physiological alterations following stress exposure adaptive?
Dr. Mathias V. Schmidt
Max Planck Institute of Psychiatry, Munich, Germany
Chronic stress is widely regarded as key risk factor for a variety of diseases, including depression. Yet, while some individuals are vulnerable to stress, others are remarkably resilient. It seems clear that genetic predispositions interact with environmental demands such as chronic stress and modulate its long-term outcome. In addition, there is abundant evidence that environmental circumstances early in life are capable of shaping the adult phenotype. In the last years two seemingly opposing views on early life stress have emerged, the two-hit model and the mismatch model. While the first hypothesis states that aversive experiences early in life predispose individuals to be more vulnerable to aversive challenges later in life, the second hypothesis argues that aversive experiences early in life result in individuals that are better adapted to aversive challenges later in life. There are published data that support either hypotheses, but the interaction with genetic predispositions has rarely been addressed. In my presentation I will propose that both views may be accurate and that the outcome of an early-life stress exposure depend on the genetic background of the individual. In addition, even within the same individual certain phenotypes may be progressively affected by multiple stress exposures (two-hit model), while other phenotypes would be most affected under mismatched conditions. I will illustrate the potential of genetic variations to modulate the outcome of early life adversity and discuss research strategies necessary to address the issue of genetic*development*environment interaction.
Insect inspired robotics:from unmanned micro-aerial-vehicles to the Mars explorer
Lecture
Tuesday, February 11, 2014
Hour: 12:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Insect inspired robotics:from unmanned micro-aerial-vehicles to the Mars explorer
Prof. Amir Ayali
Dept of Zoology, Faculty of Life Sciences Tel Aviv University
Insects are an inexhaustible source for scientists who desire to inspire ideas, processes, structures and functions from biology and implement them into engineering, specifically those interested in locomotion and in the improvement of robot mobility. Novel insights are offered based on a collaborative and combined approach that includes high-speed video monitoring of behavior, electrophysiological recordings of nerves and muscles activity, mathematical modeling and computer simulations. An overview will be presented of several different research projects focusing on cockroach running, caterpillar crawling (soft robotics), locust jumping, flight (remote control), and swarming.
Resolution of Ambiguity:Clues to the Mechanisms of Reading
Lecture
Tuesday, February 4, 2014
Hour: 12:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Resolution of Ambiguity:Clues to the Mechanisms of Reading
Prof. Zohar Eviatar
Dept of Psychology and the Institute of Information Processing and Decision Making (IIPDM)
University of Haifa
The human race has been reading and writing for only 5,000 years, suggesting that the mechanisms for these processes involve both cultural evolution and biological exaptation. Brain mechanisms of reading are hard to discern because skilled reading is so fast and efficient. Use of ambiguous words allows us to slow down some of these processes and explore the interactions of orthographic, phonological, and semantic processes. We took advantage of the characteristics of Hebrew to explore the relative effects of phonological and semantic ambiguity on access to meaning. Twenty-three participants performed a semantic decision talk on pairs of words. Half the pairs were constituted of two unambiguous words, and in half, the first word was either a homophonic homograph (like bank), or a heterophonic homograph (like tear). Our procedure allowed us to separately examine two stages of the access to meaning: the activation of multiple meanings, and then the selection of the appropriate meaning. Previous imaging studies of ambiguity resolution have not made this distinction. In the first stage, we show that different regions of the left hemisphere respond differentially to homophones and to heterophones in both whole brain analysis and in ROI comparisons of sub-regions of both anterior and posterior regions of the left hemisphere. In the second stage, in meaning selection, we again see different effects that are dependent of the phonological status of the ambiguous word, and also similar effects of the interaction between frequency effects and contextual effects in the two hemispheres. We interpret these findings in the context of a brain model of reading.
Mechanisms of local circuit dynamics in freely moving animals
Lecture
Monday, January 27, 2014
Hour: 12:30
Location:
Gerhard M.J. Schmidt Lecture Hall
Mechanisms of local circuit dynamics in freely moving animals
Dr. Eran Stark
NYU Neuroscience Institute
Langone Medical Center New York University
Much of what we know about how neurons interact and form ensemble activity patterns comes from recordings in cell cultures, brain slices, and anesthetized animals, yet dynamics in the intact brain of a behaving animal might differ. I will describe an approach to the study of local circuit dynamics in freely-moving animals, namely the combination of high-density extracellular recordings coupled with multi-site/multi-color optogenetic stimulation, combined with in-vivo pharmacology. This approach, applied to the rodent neocortex and hippocampus, yielded surprising insight into mechanisms of multiple phenomena, including spiking regime resonance, the generation of high-frequency oscillations, and spike phase precession.
Mechanisms of vocal learning in songbirds and humans
Lecture
Monday, January 20, 2014
Hour: 14:30
Location:
Wolfson Building for Biological Research
Mechanisms of vocal learning in songbirds and humans
Dr. Dina Lipkind
Hunter College
The City University of New York
Songbirds are a great model for studying how the brain solves the challenges of vocal imitation, since, like human infants, young songbirds learn to produce complex vocal sequences that are exact copies of those of adult conspecifics. This feat is thought to be accomplished by matching the bird's motor performance to a memorized sensory template. To study this process experimentally, we use a computer interface that presents birds with specific vocal imitation tasks and records their entire vocal output during the process.
Applying this methodology to vocal combinatorial learning, we trained juvenile zebra finches to swap syllable order in their song, or insert a new syllable into a string. Surprisingly, solving these tasks required a prolonged stage of learning new transitions between syllables one by one, indicating that the ability to rearrange vocal sounds is not the starting point of vocal learning, but a laboriously achieved endpoint. Analysis of babbling development data of human infants revealed that infants face a similar challenge in acquiring new transitions between syllables, suggesting that birds and humans share a common developmental stage of gradually learning to combine sounds into sequences.
In a current set of experiments, I am testing hypotheses about the computations involved in sensori-motor vocal learning. For example, is the motor output matched to the sensory template as a single unit, or is the match computed independently for different levels of the song hierarchy? Preliminary results suggest that matching vocal performance to the template occurs independently on at least two levels: the level of individual syllables, and the level of syllable sequences, suggesting that learning on these levels is carried out by distinct neural mechanisms.
Pages
2014
All events, 2014
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