Mechanisms of neural specification from embryonic stem cells
... involved, and the exact contribution of each mechanism remains controversial [8]. Besides most of the data accumulated so far were obtained in non-mammalian organisms, leaving open the question of the mechanisms of neural induction in mammals, which have now started to be addressed using ES cells. W ...
... involved, and the exact contribution of each mechanism remains controversial [8]. Besides most of the data accumulated so far were obtained in non-mammalian organisms, leaving open the question of the mechanisms of neural induction in mammals, which have now started to be addressed using ES cells. W ...
Habit formation
... the activity accentuates the boundaries of the maze runs. The majority of task-responsive neurons exhibit a burst of firing activity as the run is initiated, or as the run is completed, or both, resulting in an ensemble representation of both the beginning and end of the run. Often there is an addit ...
... the activity accentuates the boundaries of the maze runs. The majority of task-responsive neurons exhibit a burst of firing activity as the run is initiated, or as the run is completed, or both, resulting in an ensemble representation of both the beginning and end of the run. Often there is an addit ...
On the Role of the Pontine Brainstem in Vocal Pattern Generation: A
... Neuronal activity was recorded during all call types uttered. Quantitative data analysis was done for two highly frequency-modulated call types with a rhythmical character (trill, cackle), a high-pitched (peep), and a low-pitched nonrhythmic call (caw). Examples of these call types are depicted in F ...
... Neuronal activity was recorded during all call types uttered. Quantitative data analysis was done for two highly frequency-modulated call types with a rhythmical character (trill, cackle), a high-pitched (peep), and a low-pitched nonrhythmic call (caw). Examples of these call types are depicted in F ...
Spiking neural networks for vision tasks
... A method that can simplify the work with SNN was proposed in [13]. While learning methods are very well developed for frame based CNNs, they are still an open research problem for frame free spiking neural networks. the presented method avoids this problem by transforming a regular CNN, trained with ...
... A method that can simplify the work with SNN was proposed in [13]. While learning methods are very well developed for frame based CNNs, they are still an open research problem for frame free spiking neural networks. the presented method avoids this problem by transforming a regular CNN, trained with ...
Are Bigger Brains Better?
... of the same. Consider the visual system. The compound eye of the fruit fly D. melanogaster has 700 functional units, the ommatidia [32]. Within insects, larger species typically have larger eyes with higher spatial resolution; a large dragonfly can have as many as 30,000 ommatidia [33]. However, the ...
... of the same. Consider the visual system. The compound eye of the fruit fly D. melanogaster has 700 functional units, the ommatidia [32]. Within insects, larger species typically have larger eyes with higher spatial resolution; a large dragonfly can have as many as 30,000 ommatidia [33]. However, the ...
Challenges for Brain Emulation
... axon hillock, or the synapse, where spikes are transformed into post-synaptic potentials. The Hodgkin-Huxley [ 4] biological neural model discussed earlier, with Ca++, Na+, and K+ currents through ion channels, can require relatively expensive computations. Simulation is further complicated when one ...
... axon hillock, or the synapse, where spikes are transformed into post-synaptic potentials. The Hodgkin-Huxley [ 4] biological neural model discussed earlier, with Ca++, Na+, and K+ currents through ion channels, can require relatively expensive computations. Simulation is further complicated when one ...
(addl. 3)
... axon hillock, or the synapse, where spikes are transformed into post-synaptic potentials. The Hodgkin-Huxley [ 4] biological neural model discussed earlier, with Ca++, Na+, and K+ currents through ion channels, can require relatively expensive computations. Simulation is further complicated when one ...
... axon hillock, or the synapse, where spikes are transformed into post-synaptic potentials. The Hodgkin-Huxley [ 4] biological neural model discussed earlier, with Ca++, Na+, and K+ currents through ion channels, can require relatively expensive computations. Simulation is further complicated when one ...
Introduction - KFUPM Faculty List
... adjacent forward layer. If, however, some of the communication links are missing from the network, we say that the network is partially connected. 1.4.3 Recurrent Networks A recurrent neural network distinguishes itself from the feed-forward network in that it has at least one feedback loop. For exa ...
... adjacent forward layer. If, however, some of the communication links are missing from the network, we say that the network is partially connected. 1.4.3 Recurrent Networks A recurrent neural network distinguishes itself from the feed-forward network in that it has at least one feedback loop. For exa ...
Barlow, Horace (2001) - Cambridge Neuroscience
... active neurons. The article also develops the idea of sparse coding, where the activity of a small number of neurons selected from a very large population forms a distributed representation of the sensory input (see also Field 1994). The elements of this type of distributed representation are called ...
... active neurons. The article also develops the idea of sparse coding, where the activity of a small number of neurons selected from a very large population forms a distributed representation of the sensory input (see also Field 1994). The elements of this type of distributed representation are called ...
Polarization-sensitive and light-sensitive neurons in two parallel
... was moved into the light path. Stimuli were applied from the zenith and, for unpolarized light flashes, also from lateral to the right and left eye (0° elevation, in a few experiments 30° elevation, duration of unpolarized light stimuli 1.5-3 s). The angular extent of the stimulus at the locust’s ey ...
... was moved into the light path. Stimuli were applied from the zenith and, for unpolarized light flashes, also from lateral to the right and left eye (0° elevation, in a few experiments 30° elevation, duration of unpolarized light stimuli 1.5-3 s). The angular extent of the stimulus at the locust’s ey ...
Chapter 15 - Las Positas College
... that provide a stable internal environment for you. Some of the important visceral functions under the regulation of the ANS are maintenance of heart rate and blood pressure, digestion, and urination. Anatomically, the ANS is described as a motor (efferent) pathway made up of two neurons, and Chapte ...
... that provide a stable internal environment for you. Some of the important visceral functions under the regulation of the ANS are maintenance of heart rate and blood pressure, digestion, and urination. Anatomically, the ANS is described as a motor (efferent) pathway made up of two neurons, and Chapte ...
Direction of action is represented in the ventral premotor cortex
... location of a target, specified in an external coordinate frame, into a set of muscle activation patterns, specified in an intrinsic coordinate frame. Insight into the sensorimotor transformations involved in this process1,2 and how these transformations are implemented in the central nervous system ...
... location of a target, specified in an external coordinate frame, into a set of muscle activation patterns, specified in an intrinsic coordinate frame. Insight into the sensorimotor transformations involved in this process1,2 and how these transformations are implemented in the central nervous system ...
LESSON 4.3 WORKBOOK What makes us go to sleep, and what
... A flip-flop switch has one important advantage – when it switches from one state to another, it does so quickly. Clearly, it is to our advantage to be either asleep or awake. A state that has some of the characteristics of both sleep and wakefulness would be quite problematic! Controlling the switch ...
... A flip-flop switch has one important advantage – when it switches from one state to another, it does so quickly. Clearly, it is to our advantage to be either asleep or awake. A state that has some of the characteristics of both sleep and wakefulness would be quite problematic! Controlling the switch ...
A visual processing task: Retina and V1
... all that the cell does? How well does a bigger bar work, how about a ’T’-shape instead of a bar? This raises the general question: how to measure the receptive field of a cell without biasing the result, or, how to know what the cell codes for? A big problem in answering this question is the enormou ...
... all that the cell does? How well does a bigger bar work, how about a ’T’-shape instead of a bar? This raises the general question: how to measure the receptive field of a cell without biasing the result, or, how to know what the cell codes for? A big problem in answering this question is the enormou ...
Structure and function in the cerebral ganglion
... the species, the type of electrode used and its placement, the oscillations have various waveforms, but they are always continuous at a frequency of approximately 0.7 Hz. Similar oscillations have been reported in a number of olfactory structures from other animals, both invertebrate and invertebrat ...
... the species, the type of electrode used and its placement, the oscillations have various waveforms, but they are always continuous at a frequency of approximately 0.7 Hz. Similar oscillations have been reported in a number of olfactory structures from other animals, both invertebrate and invertebrat ...
The basic Hebb rule
... Non-Hebbian forms of synaptic plasticity • They modify synaptic strengths solely on the basis of pre- or postsynaptic firing, are likely to play important roles in homeostatic, developmental, and learning processes • Homeostatic plasticity －It allows neurons to sense how active they are and to adju ...
... Non-Hebbian forms of synaptic plasticity • They modify synaptic strengths solely on the basis of pre- or postsynaptic firing, are likely to play important roles in homeostatic, developmental, and learning processes • Homeostatic plasticity －It allows neurons to sense how active they are and to adju ...
The role of temporal parameters in a thalamocortical model of analogy
... A more difficult issue is how filtering can be done, i.e., how can input-driven cortical activity be distinguished from cortex-driven cortical activity? As suggested in [27] and [28], the TRN is a promising location where such a filtering can occur. The basic idea is that the reticular neurons recei ...
... A more difficult issue is how filtering can be done, i.e., how can input-driven cortical activity be distinguished from cortex-driven cortical activity? As suggested in [27] and [28], the TRN is a promising location where such a filtering can occur. The basic idea is that the reticular neurons recei ...
ch15 autonomic nervous system
... B. Adrenergic Neurons and Adrenergic Receptors 1. The adrenergic neurons release norepinephrine (Figure 15.7) and include most sympathetic postganglionic neurons. 2. The main types of adrenergic receptors are alpha and beta receptors. a. These receptors are further classified into subtypes. b. Depen ...
... B. Adrenergic Neurons and Adrenergic Receptors 1. The adrenergic neurons release norepinephrine (Figure 15.7) and include most sympathetic postganglionic neurons. 2. The main types of adrenergic receptors are alpha and beta receptors. a. These receptors are further classified into subtypes. b. Depen ...
Zebrafish and motor control over the last decade
... during routine swimming, after it has developed a swim bladder to allow it to move from the bottom up into the water column (Borla et al., 2002). Remarkably the larval fish can swim over a very large range of bending frequencies from roughly 15 Hz to 100 Hz (Budick and O'Malley, 2000; Muller and van ...
... during routine swimming, after it has developed a swim bladder to allow it to move from the bottom up into the water column (Borla et al., 2002). Remarkably the larval fish can swim over a very large range of bending frequencies from roughly 15 Hz to 100 Hz (Budick and O'Malley, 2000; Muller and van ...
Spontaneous firing patterns of identified spiny neurons in the rat
... for the occurrence of such phasic responses. These studies have not determined whether such bursts of action potentials represent a characteristic pattern of the neostriatal outflow, or rather the activity of interneurons involved in the local processing of afferent activity. A minority of neostriat ...
... for the occurrence of such phasic responses. These studies have not determined whether such bursts of action potentials represent a characteristic pattern of the neostriatal outflow, or rather the activity of interneurons involved in the local processing of afferent activity. A minority of neostriat ...
Discussion and future directions
... Put generally, it demonstrates that a self–organizing map can learn to distinctively represent and command 12 directions of movement, by extracting the similarity relationships from the input space. The success of the self–organization process is dependent on two factors: the input patterns and the ...
... Put generally, it demonstrates that a self–organizing map can learn to distinctively represent and command 12 directions of movement, by extracting the similarity relationships from the input space. The success of the self–organization process is dependent on two factors: the input patterns and the ...
Electroencephalography: Basic Principles, Clinical Applications, and
... asynchronous UA is interrupted mainly due to inactivation. The latter process results in a disfacilitation of the upper neuronal structures and therewith to a positive fluctuation of the superficial DC/EEG potential (2). (From original tracings from Speckmann, E.J., Caspers, H., and Jansen, R.W.C. 1 ...
... asynchronous UA is interrupted mainly due to inactivation. The latter process results in a disfacilitation of the upper neuronal structures and therewith to a positive fluctuation of the superficial DC/EEG potential (2). (From original tracings from Speckmann, E.J., Caspers, H., and Jansen, R.W.C. 1 ...
firing pattern modulation by oscillatory input in
... Abstract/Neocortical neurons in vivo receive periodic stimuli due to feedforward input from the periphery as well as local cellular and circuit properties. In order to understand how neurons process such information, the responses of neurons to periodic sine wave current stimuli of varying frequenci ...
... Abstract/Neocortical neurons in vivo receive periodic stimuli due to feedforward input from the periphery as well as local cellular and circuit properties. In order to understand how neurons process such information, the responses of neurons to periodic sine wave current stimuli of varying frequenci ...
Supplementary Figure Legends - Word file
... Supplementary Figure 1: Example responses to pure tones and harmonic complex tones from a pitchselective neuron (a, d) (Unit M36n-514) and a non-pitch-selective neuron (b, e) (Unit M2p-140). a. Pure tone frequency response from a pitch-selective neuron. b. Pure tone frequency response from a non-pit ...
... Supplementary Figure 1: Example responses to pure tones and harmonic complex tones from a pitchselective neuron (a, d) (Unit M36n-514) and a non-pitch-selective neuron (b, e) (Unit M2p-140). a. Pure tone frequency response from a pitch-selective neuron. b. Pure tone frequency response from a non-pit ...
Neural oscillation
Neural oscillation is rhythmic or repetitive neural activity in the central nervous system. Neural tissue can generate oscillatory activity in many ways, driven either by mechanisms within individual neurons or by interactions between neurons. In individual neurons, oscillations can appear either as oscillations in membrane potential or as rhythmic patterns of action potentials, which then produce oscillatory activation of post-synaptic neurons. At the level of neural ensembles, synchronized activity of large numbers of neurons can give rise to macroscopic oscillations, which can be observed in the electroencephalogram (EEG). Oscillatory activity in groups of neurons generally arises from feedback connections between the neurons that result in the synchronization of their firing patterns. The interaction between neurons can give rise to oscillations at a different frequency than the firing frequency of individual neurons. A well-known example of macroscopic neural oscillations is alpha activity.Neural oscillations were observed by researchers as early as 1924 (by Hans Berger). More than 50 years later, intrinsic oscillatory behavior was encountered in vertebrate neurons, but its functional role is still not fully understood. The possible roles of neural oscillations include feature binding, information transfer mechanisms and the generation of rhythmic motor output. Over the last decades more insight has been gained, especially with advances in brain imaging. A major area of research in neuroscience involves determining how oscillations are generated and what their roles are. Oscillatory activity in the brain is widely observed at different levels of observation and is thought to play a key role in processing neural information. Numerous experimental studies support a functional role of neural oscillations; a unified interpretation, however, is still lacking.