The architectural balance of the Ventral Nerve Cord depends
... origin of the wiring cost, it increases with the distance between connected neurons. Among various functionally equivalent arrangements, the one having the closest-connected neurons is assumed to be the most strongly selected (Chklovskii & Koulakov, 2004). Despite more than 100 years of intensive st ...
... origin of the wiring cost, it increases with the distance between connected neurons. Among various functionally equivalent arrangements, the one having the closest-connected neurons is assumed to be the most strongly selected (Chklovskii & Koulakov, 2004). Despite more than 100 years of intensive st ...
Memory Maintenance in Synapses with Calcium
... due to the lower extracellular calcium concentration in vivo on the time scale of synaptic decay has not been considered heretofore. In the present paper, we study the persistence of synaptic changes, first in a synapse connecting a pair of independent Poisson neurons, and second in a large network ...
... due to the lower extracellular calcium concentration in vivo on the time scale of synaptic decay has not been considered heretofore. In the present paper, we study the persistence of synaptic changes, first in a synapse connecting a pair of independent Poisson neurons, and second in a large network ...
View PDF - MRC BNDU - University of Oxford
... Cell density per segment was obtained by dividing the estimated number of neurons per segment in each animal by the total segment volume, then taking the mean across animals. For sections processed by both in situ hybridization and IHC, we could not use an optical fractionator as the silver grains r ...
... Cell density per segment was obtained by dividing the estimated number of neurons per segment in each animal by the total segment volume, then taking the mean across animals. For sections processed by both in situ hybridization and IHC, we could not use an optical fractionator as the silver grains r ...
Downloadable Full Text - DSpace@MIT
... they are the primary source of DA in target structures such as the medial prefrontal cortex (mPFC) and nucleus accumbens (NAc), which play important roles in a broad range of motivated behaviors and neuropsychiatric disorders1-3. Although DA neuron activity often correlates with a reward prediction ...
... they are the primary source of DA in target structures such as the medial prefrontal cortex (mPFC) and nucleus accumbens (NAc), which play important roles in a broad range of motivated behaviors and neuropsychiatric disorders1-3. Although DA neuron activity often correlates with a reward prediction ...
Open-loop organization of thalamic reticular nucleus and dorsal
... synapse, since this synapse induces large postsynaptic currents but is highly depressing (Chung et al. 2002; Gil et al. 1999; Stratford et al. 1996), a burst of action potentials arriving after a period of quiescence (as required by the voltage- and time sensitivity of T-type calcium channels) would ...
... synapse, since this synapse induces large postsynaptic currents but is highly depressing (Chung et al. 2002; Gil et al. 1999; Stratford et al. 1996), a burst of action potentials arriving after a period of quiescence (as required by the voltage- and time sensitivity of T-type calcium channels) would ...
Articles in PresS. J Neurophysiol (March 20, 2003). 10.1152/jn
... neurons. We recognize that the si K+ current is likely to arise from at least two channel types, but for the sake of simplicity we have treated it as a single conductance. This combined outward current acts in opposition to inward ionic and synaptic currents to regulate membrane potential in the up/ ...
... neurons. We recognize that the si K+ current is likely to arise from at least two channel types, but for the sake of simplicity we have treated it as a single conductance. This combined outward current acts in opposition to inward ionic and synaptic currents to regulate membrane potential in the up/ ...
Focal local field potential (LFP) signature of the single
... located on somas or dendrites proximal to soma (White et al., 1984; Keller and White, 1987; Staiger et al., 1996; Ahmed et al., 1997; Porter et al., 2001; Bagnall et al., 2011), while thalamic projections on RS cells are predominantly located on spines in the dendritic arbors (Keller and White, 1987 ...
... located on somas or dendrites proximal to soma (White et al., 1984; Keller and White, 1987; Staiger et al., 1996; Ahmed et al., 1997; Porter et al., 2001; Bagnall et al., 2011), while thalamic projections on RS cells are predominantly located on spines in the dendritic arbors (Keller and White, 1987 ...
Focal local field potential (LFP) signature of the single
... located on somas or dendrites proximal to soma (White et al., 1984; Keller and White, 1987; Staiger et al., 1996; Ahmed et al., 1997; Porter et al., 2001; Bagnall et al., 2011), while thalamic projections on RS cells are predominantly located on spines in the dendritic arbors (Keller and White, 1987 ...
... located on somas or dendrites proximal to soma (White et al., 1984; Keller and White, 1987; Staiger et al., 1996; Ahmed et al., 1997; Porter et al., 2001; Bagnall et al., 2011), while thalamic projections on RS cells are predominantly located on spines in the dendritic arbors (Keller and White, 1987 ...
Descending Systems Translate Transient Cortical Commands into a
... a 2D wrist task designed to dissociate motor parameters (Kakei et al. 1999). Here, we show that the directional-torque tuning of single cortical and spinal neurons had a similar shape but different spatiotemporal distributions: Cortical neurons expressed a temporally transient and spatially uniform ...
... a 2D wrist task designed to dissociate motor parameters (Kakei et al. 1999). Here, we show that the directional-torque tuning of single cortical and spinal neurons had a similar shape but different spatiotemporal distributions: Cortical neurons expressed a temporally transient and spatially uniform ...
Biophysics of Extracellular Action Potentials
... action potential (IAP). I find that the IAP method underconstrains the parameters. The distinguishing characteristics of the EAP constrain the parameters and are fairly invariant to electrode position and cellular morphology. I conclude that matching EAP recordings are an excellent means of constrai ...
... action potential (IAP). I find that the IAP method underconstrains the parameters. The distinguishing characteristics of the EAP constrain the parameters and are fairly invariant to electrode position and cellular morphology. I conclude that matching EAP recordings are an excellent means of constrai ...
Antennal Mechanosensory Neurons Mediate Wing Motor Reflexes
... air puff, we generated constant airflow with an air pump (Cole Parmer Instrument) connected to a flow controller (King Instrument) and briefly switched the flow toward the fly using a 3-way valve (Parker Hannifin). To exclude the effect of the air puff and to avoid segments when flies were not flyin ...
... air puff, we generated constant airflow with an air pump (Cole Parmer Instrument) connected to a flow controller (King Instrument) and briefly switched the flow toward the fly using a 3-way valve (Parker Hannifin). To exclude the effect of the air puff and to avoid segments when flies were not flyin ...
Glutamate Inhibits GABA Excitatory Activity in
... suggest that GABAergic activity develops early and that glutamate activity occurs soon after. This raises the question as to the possible interaction between the two primary transmitters of the brain during early development. If both GABA and glutamate are excitatory, what prevents the neurons in th ...
... suggest that GABAergic activity develops early and that glutamate activity occurs soon after. This raises the question as to the possible interaction between the two primary transmitters of the brain during early development. If both GABA and glutamate are excitatory, what prevents the neurons in th ...
Propagation of cortical synfire activity: survival probability in single
... packet input, was computed. Interpreting a and s as deterministic state variables, we could predict the propagation of synchronous activity in a syn®re chain network on the basis of the transmission function. Practically identical results were obtained for a reduced integrate-and-®re model, demonstr ...
... packet input, was computed. Interpreting a and s as deterministic state variables, we could predict the propagation of synchronous activity in a syn®re chain network on the basis of the transmission function. Practically identical results were obtained for a reduced integrate-and-®re model, demonstr ...
Chapter 02: Biopsychology, Neuroscience, and Human Nature
... b. transport messages between sensory neurons and motor neurons. c. are the same as sensory neurons that are sensitive to external stimuli. d. communicate directly with motor neurons in the peripheral nervous system. e. continuously monitor the routine operation of the body's internal functions. Dif ...
... b. transport messages between sensory neurons and motor neurons. c. are the same as sensory neurons that are sensitive to external stimuli. d. communicate directly with motor neurons in the peripheral nervous system. e. continuously monitor the routine operation of the body's internal functions. Dif ...
Surgical principles of peripheral nerve repair
... Tumor capsule ‘baskets’ nerve fascicles apart- fascicles are adhered & not incorporated into it Intracapsular dissection of tumor with or without internal ...
... Tumor capsule ‘baskets’ nerve fascicles apart- fascicles are adhered & not incorporated into it Intracapsular dissection of tumor with or without internal ...
M1 Corticospinal Mirror Neurons and Their Role in
... cortex (M1) respond during action observation [1, 2], a property first shown for mirror neurons in monkey premotor cortex [3]. We now show for the first time that the discharge of a major class of M1 output neuron, the pyramidal tract neuron (PTN), is modulated during observation of precision grip b ...
... cortex (M1) respond during action observation [1, 2], a property first shown for mirror neurons in monkey premotor cortex [3]. We now show for the first time that the discharge of a major class of M1 output neuron, the pyramidal tract neuron (PTN), is modulated during observation of precision grip b ...
Brain stem excitatory and inhibitory signaling pathways regulating
... which can be modulated by alterations in activity of neutral endopeptidases (156). In addition, endogenous substance P facilitates synaptic transmission in airway parasympathetic ganglia (34, 154), similar to the effect observed with cyclooxygenase activation and the release of prostaglandins in ant ...
... which can be modulated by alterations in activity of neutral endopeptidases (156). In addition, endogenous substance P facilitates synaptic transmission in airway parasympathetic ganglia (34, 154), similar to the effect observed with cyclooxygenase activation and the release of prostaglandins in ant ...
How Inhibition Shapes Cortical Activity
... rectifying K+ (GIRK) channels (Lüscher et al., 1997). It has been suggested that synaptically released GABA from a large number of coactive interneurons must be pooled or accumulated to activate GABAB receptors (Isaacson et al., 1993; Scanziani, 2000). Postsynaptic GABAB receptors also inhibit volt ...
... rectifying K+ (GIRK) channels (Lüscher et al., 1997). It has been suggested that synaptically released GABA from a large number of coactive interneurons must be pooled or accumulated to activate GABAB receptors (Isaacson et al., 1993; Scanziani, 2000). Postsynaptic GABAB receptors also inhibit volt ...
Perception Spike Timing-Dependent Plasticity: From Synapse to
... that LTP of the associational/commissural connections can be induced by pairing spike bursts in the mossy fibers and the association/commissural pathway, and this effect depends on the order and interval between the pre/post bursts rather than between individual spikes. For a synaptic learning rule ...
... that LTP of the associational/commissural connections can be induced by pairing spike bursts in the mossy fibers and the association/commissural pathway, and this effect depends on the order and interval between the pre/post bursts rather than between individual spikes. For a synaptic learning rule ...
Refinement of feedforward projections, neuronal density, and
... the density and distribution of boutons in feedforward projections, which are those that originate in area 17 and extend to extrastriate areas (Callaway, 2004). By studying the distribution of synaptic zinc in the ferret visual cortex, Khalil and Levitt (2013) found evidence for a similar developmen ...
... the density and distribution of boutons in feedforward projections, which are those that originate in area 17 and extend to extrastriate areas (Callaway, 2004). By studying the distribution of synaptic zinc in the ferret visual cortex, Khalil and Levitt (2013) found evidence for a similar developmen ...
Spike Timing-Dependent Plasticity: From Synapse to Perception
... The simplest explanation for the post-pre LTD window is that the afterdepolarization associated with the AP causes a partial opening of NMDARs, resulting in a lowlevel Ca2⫹ influx required for LTD induction. However, such a simple model inevitably predicts the existence of a LTD window at positive ( ...
... The simplest explanation for the post-pre LTD window is that the afterdepolarization associated with the AP causes a partial opening of NMDARs, resulting in a lowlevel Ca2⫹ influx required for LTD induction. However, such a simple model inevitably predicts the existence of a LTD window at positive ( ...
Neuronal innervation of the exocrine defence glands in stick insects
... They increase the potential for survival and thus contribute to the individual fitness of an organism. Two modes of defence are commonly distinguished: primary defence mechanisms (avoiding detection or contact, e. g. by crypsis) and secondary defence mechanisms (defence elicited only after detection ...
... They increase the potential for survival and thus contribute to the individual fitness of an organism. Two modes of defence are commonly distinguished: primary defence mechanisms (avoiding detection or contact, e. g. by crypsis) and secondary defence mechanisms (defence elicited only after detection ...
Receptive Fields of Second-order Neurons in the Olfactory Bulb of
... existence of a spatially organized projection of receptor neurons onto the second-order mitral cells in the olfactory bulb. Evidence suggesting a spatial organization of projections has been reported in a number of studies (Le Gros Clark, 1951; Mozell, 1958; Land et al., 1970; Land, 1973; Land and S ...
... existence of a spatially organized projection of receptor neurons onto the second-order mitral cells in the olfactory bulb. Evidence suggesting a spatial organization of projections has been reported in a number of studies (Le Gros Clark, 1951; Mozell, 1958; Land et al., 1970; Land, 1973; Land and S ...
Relative Contributions of Specific Activity Histories and
... Although these conclusions were derived mainly from studies in reduced systems (cell and organotypic cultures), they are not limited to these settings [4,8,14,15]. Thus, for example, it has recently been shown that synapse size fluctuations in the cerebral cortex of adult mice are at least as large ...
... Although these conclusions were derived mainly from studies in reduced systems (cell and organotypic cultures), they are not limited to these settings [4,8,14,15]. Thus, for example, it has recently been shown that synapse size fluctuations in the cerebral cortex of adult mice are at least as large ...
specification of synaptic connections mediating the simple stretch
... and they develop a phenotype that is also appropriate for this location. Although these experiments examined the fate of autonomic rather than sensory neurones, it seemed possible that a similar result might apply to sensory neurones as well. We tested this idea by replacing the single brachial DRG ...
... and they develop a phenotype that is also appropriate for this location. Although these experiments examined the fate of autonomic rather than sensory neurones, it seemed possible that a similar result might apply to sensory neurones as well. We tested this idea by replacing the single brachial DRG ...
Axon
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An axon (from Greek ἄξων áxōn, axis), also known as a nerve fibre, is a long, slender projection of a nerve cell, or neuron, that typically conducts electrical impulses away from the neuron's cell body. The function of the axon is to transmit information to different neurons, muscles and glands. In certain sensory neurons (pseudounipolar neurons), such as those for touch and warmth, the electrical impulse travels along an axon from the periphery to the cell body, and from the cell body to the spinal cord along another branch of the same axon. Axon dysfunction causes many inherited and acquired neurological disorders which can affect both the peripheral and central neurons.An axon is one of two types of protoplasmic protrusions that extrude from the cell body of a neuron, the other type being dendrites. Axons are distinguished from dendrites by several features, including shape (dendrites often taper while axons usually maintain a constant radius), length (dendrites are restricted to a small region around the cell body while axons can be much longer), and function (dendrites usually receive signals while axons usually transmit them). All of these rules have exceptions, however.Some types of neurons have no axon and transmit signals from their dendrites. No neuron ever has more than one axon; however in invertebrates such as insects or leeches the axon sometimes consists of several regions that function more or less independently of each other. Most axons branch, in some cases very profusely.Axons make contact with other cells—usually other neurons but sometimes muscle or gland cells—at junctions called synapses. At a synapse, the membrane of the axon closely adjoins the membrane of the target cell, and special molecular structures serve to transmit electrical or electrochemical signals across the gap. Some synaptic junctions appear partway along an axon as it extends—these are called en passant (""in passing"") synapses. Other synapses appear as terminals at the ends of axonal branches. A single axon, with all its branches taken together, can innervate multiple parts of the brain and generate thousands of synaptic terminals.