Abstract:
:1. We describe a four-layered neural network (Fig. 1), based on the input organization of a collision signaling neuron in the visual system of the locust, the lobula giant movement detector (LGMD). The 250 photoreceptors ("P" units) in layer 1 are excited by any change in illumination, generated when an image edge passes over them. Layers 2 and 3 incorporate both excitatory and inhibitory interactions, and layer 4 consists of a single output element, equivalent to the locust LGMD. 2. The output element of the neural network, the "LGMD", responds directionally when challenged with approaching versus receding objects, preferring approaching objects (Figs. 2-4). The time course and shape of the "LGMD" response matches that of the LGMD (Fig. 4). Directionality is maintained with objects of various sizes and approach velocities. The network is tuned to direct approach (Fig. 5). The "LGMD" shows no directional selectivity for translatory motion at a constant velocity across the "eye", but its response increases with edge velocity (Figs. 6 and 9). 3. The critical image cues for a selective response to object approach by the "LGMD" are edges that change in extent or in velocity as they move (Fig. 7). Lateral inhibition is crucial to the selectivity of the "LGMD" and the selective response is abolished or else much reduced if lateral inhibition is taken out of the network (Fig. 7). We conclude that lateral inhibition in the neuronal network for the locust LGMD also underlies the experimentally observed critical image cues for its directional response. 4. Lateral inhibition shapes the velocity tuning of the network for objects moving in the X and Y directions without approaching the eye (see Fig. 1). As an edge moves over the eye at a constant velocity, a race occurs between the excitation that is caused by edge movement and which passes down the network and the inhibition that passes laterally. Excitation must win this race for units in layer 3 to reach threshold (Fig. 8). The faster the edge moves over the eye the more units in layer 3 reach threshold and pass excitation on to the "LGMD" (Fig. 9). 5. Lateral inhibition shapes the tuning of the network for objects moving in the Z direction, toward or away from the eye (see Fig. 1). As an object approaches the eye there is a buildup of excitation in the "LGMD" throughout the movement whereas the response to object recession is often brief, particularly for high velocities. During object motion, a critical race occurs between excitation passing down the network and inhibition directed laterally, excitation must win this race for the rapid buildup in excitation in the "LGMD" as seen in the final stages of object approach (Figs. 10-12). The buildup is eliminated if, during object approach, excitation cannot win this race (as happens when the spread of inhibition laterally takes < 1 ms Fig. 13, D and E). Taking all lateral inhibition away increases the "LGMD" response to object approach, but overall directional selectivity is reduced as there is also a lot of residual network excitation following object recession (Fig. 13B). 6. Directional selectivity for rapidly approaching objects is further enhanced at the level of the "LGMD" by the timing of a feed-forward, inhibitory loop onto the "LGMD", activated when a large number of receptor units are excited in a short time. The inhibitory loop is activated at the end of object approach, truncating the excitatory "LGMD" response after approach has ceased, but at the initiation of object recession (*Fig. 2, 3, and 13). Eliminating the feed-forward, inhibitory loop prolongs the "LGMD" response to both receding and approaching objects (Fig. 13F).
journal_name
J Neurophysioljournal_title
Journal of neurophysiologyauthors
Rind FC,Bramwell DIdoi
10.1152/jn.1996.75.3.967subject
Has Abstractpub_date
1996-03-01 00:00:00pages
967-85issue
3eissn
0022-3077issn
1522-1598journal_volume
75pub_type
杂志文章abstract::1. Neuronlike differentiation of Y-79 retinoblastoma was chemically induced in vitro, by plating the cells onto a poly-D-lysine and laminin substrate. The changes in voltage-dependent conductances after 48-72 h were examined with the whole-cell tight-seal and the perforated-patch recording techniques. 2. Although outw...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1993.70.4.1487
更新日期:1993-10-01 00:00:00
abstract::Our understanding of how we learn and retain motor behaviors is still limited. For instance, there is conflicting evidence as to whether the memory of a learned visuomotor perturbation consolidates; i.e., the motor memory becomes resistant to interference from learning a competing perturbation over time. Here, we soug...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00178.2016
更新日期:2017-01-01 00:00:00
abstract::In contrast to hand movements, the existence of a neural representation of saccade kinematics is unclear. Saccade kinematics is typically thought to be specified by motor error/desired displacement and generated by brain stem circuits that are not penetrable to voluntary control. We studied the influence of instructed...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00329.2017
更新日期:2017-09-01 00:00:00
abstract::Movement duration is an integral component of motor control, but nearly all extant optimization models of motor planning prefix duration instead of explaining it. Here we propose a new optimization principle that predicts movement duration. The model assumes that the brain attempts to minimize movement duration under ...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00751.2005
更新日期:2006-06-01 00:00:00
abstract::A brain slice preparation from guinea pigs and intracellular recording techniques were used to examine the effects of carbachol application on the three classes (A, B, and C) of neurons (n = 68, 40 of class A, 12 of class B, 16 of class C) within the mediolateral part of the lateral septum (LSml). Bath application of ...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1998.80.3.1042
更新日期:1998-09-01 00:00:00
abstract::To clarify the role of cholinergic inputs to the intermediate layer of the superior colliculus (SC), we examined the effect of microinjection of nicotine into the SC on visually guided saccades in macaque monkeys. After injection of 0.4-2 microl of 1-100 mM nicotine into the SC, frequency of extremely short latency sa...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1999.82.3.1642
更新日期:1999-09-01 00:00:00
abstract::Control of the spatial orientation of the hand is an important component of reaching and grasping movements. We studied the contribution of vision and proprioception to the perception and control of hand orientation in orientation-matching and letter-posting tasks. In the orientation-matching task, subjects aligned a ...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00980.2007
更新日期:2008-04-01 00:00:00
abstract::Single-unit electrical activity has been recorded from 122 viscerosomatic neurons in the T9 and T11 segments of the cat's spinal cord. These neurons were excited by electrical and/or natural stimulation of visceral and somatic afferent fibers. The majority of viscerosomatic neurons (72%) received somatic nociceptive i...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1986.56.3.785
更新日期:1986-09-01 00:00:00
abstract::When identical stimuli are presented in rapid temporal succession, neural responses to the second stimulation are often weaker than those observed for the first. This phenomenon is termed sensory gating and is believed to be an adaptive feature that helps prevent higher-order cortical centers from being flooded with u...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00260.2017
更新日期:2017-10-01 00:00:00
abstract::The interstitial nucleus of Cajal (INC) is thought to control torsional and vertical head posture. Unilateral microstimulation of the INC evokes torsional head rotation to positions that are maintained until stimulation offset. Unilateral INC inactivation evokes head position-holding deficits with the head tilted in t...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.90363.2008
更新日期:2008-09-01 00:00:00
abstract::1. We examined the role of gamma-aminobutyric acid (GABA)-mediated inhibition in shaping excitatory tuning curves and creating selectivity for frequency-modulated (FM) sweeps in 29 neurons in the central nucleus of the inferior colliculus (ICC) of the pallid bat, with the use of single-unit recording coupled with the ...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1996.76.2.1059
更新日期:1996-08-01 00:00:00
abstract::During locomotion, contacting an obstacle generates a coordinated response involving flexion of the stimulated leg and activation of extensors contralaterally to ensure adequate support and forward progression. Activation of motoneurons innervating contralateral muscles (i.e., crossed extensor reflex) has always been ...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.01274.2007
更新日期:2008-02-01 00:00:00
abstract::High-frequency burstlike electrical conditioning stimulation (HFS) applied to human skin induces an increase in mechanical pinprick sensitivity of the surrounding unconditioned skin (a phenomenon known as secondary hyperalgesia). The present study assessed the effect of frequency of conditioning stimulation on the dev...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00274.2019
更新日期:2019-09-01 00:00:00
abstract::The spatial arrangement of preferred directions (PDs) in the primary motor cortex has revealed evidence for columnar organization and short-range order. We investigated the large-scale properties of this arrangement. We recorded neural activity at sites on a grid covering a large region of the arm area of the motor co...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00488.2006
更新日期:2006-12-01 00:00:00
abstract::We measured the timing of spontaneous membrane potential fluctuations and action potentials of medial and lateral agranular corticostriatal and striatal neurons with the use of in vivo intracellular recordings in urethan-anesthetized rats. All neurons showed spontaneous subthreshold membrane potential shifts from 7 to...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1997.77.4.1697
更新日期:1997-04-01 00:00:00
abstract::Humans maneuver easily over uneven terrain. To maintain smooth and efficient gait the motor system needs to adapt the locomotor output to the walking environment. In the present study we investigate the role of sensory feedback in adjusting the soleus muscle activity during overground walking in 19 healthy volunteers....
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.91175.2008
更新日期:2009-04-01 00:00:00
abstract::It is controversial whether simple-spike activity of cerebellar Purkinje cells during arm movements encodes movement kinematics like velocity or dynamics like muscle activities. To examine this issue, we trained monkeys to flex or extend the elbow by 45 degrees in 400 ms under resistive and assistive force fields but ...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00206.2006
更新日期:2007-02-01 00:00:00
abstract::Peroneal motoneurons were recorded intracellularly in anesthetized cats during sustained submaximal contractions of peroneus brevis muscle (PB) elicited by repetitive electrical stimulation of motor axons in the distal portion of cut ventral root filaments. Mechanical stimulation of the territory innervated by the sup...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.2000.83.6.3201
更新日期:2000-06-01 00:00:00
abstract::We examined how subjects plan speeded reaching movements when the precise target of the movement is not known at movement onset. Before each reach, subjects were given only a probability distribution on possible target positions. Only after completing part of the movement did the actual target appear. In separate expe...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00858.2007
更新日期:2007-11-01 00:00:00
abstract::Tetanus toxin reduces monosynaptic inhibitory and excitatory synaptic transmission in mouse spinal cord neurons in culture. Inhibitory transmission is preferentially reduced by the toxin; however, excitatory transmission is also ultimately reduced and blocked by the concentrations of toxin used in these studies. Recor...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1987.57.1.121
更新日期:1987-01-01 00:00:00
abstract::Motor performance induces a postexercise increase in corticomotor excitability that may be associated with motor learning. We investigated whether there are hemispheric differences in the extent and/or time course of changes in corticomotor excitability following a manipulation task (Purdue pegboard) and their relatio...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00595.2003
更新日期:2004-04-01 00:00:00
abstract::Previous functional MRI studies reported neural correlates of risk and ambiguity based on behavioral economic theories. A recent study controlled for uncertainty by adding noise to information of an impending aversive event and demonstrated brain areas that did not track the degree of uncertainty: the activation peake...
journal_title:Journal of neurophysiology
pub_type: 杂志文章,评审
doi:10.1152/jn.00406.2009
更新日期:2009-08-01 00:00:00
abstract::Neurons in monkey orbitofrontal cortex (OF) are known to respond to reward-predicting cues with a strength that depends on the value of the predicted reward as determined 1) by intrinsic attributes including size and quality and 2) by extrinsic factors including the monkey's state of satiation and awareness of what ot...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00373.2005
更新日期:2005-10-01 00:00:00
abstract::A lamprey maintains the dorsal-side-up orientation due to the activity of postural control system driven by vestibular input. Visual input can affect the body orientation: illumination of one eye evokes ipsilateral roll tilt. An important element of the postural network is the reticulospinal (RS) neurons transmitting ...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.2000.83.2.864
更新日期:2000-02-01 00:00:00
abstract::Successful motor performance relies on our ability to adapt to changes in the environment by learning novel mappings between motor commands and sensory outcomes. Such adaptation is thought to involve two distinct mechanisms: an implicit, error-based component linked to slow learning and an explicit, strategic componen...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00113.2018
更新日期:2018-10-01 00:00:00
abstract::1. Intracellular recordings were made from neurons of the basolateral amygdala (BLA) in in vitro slice preparations to determine long-term differences in metabotropic glutamate receptor (mGluR) agonist-induced membrane responses in control and amygdala-kindled rats. 2. (2S,3S,4S)-alpha-(carboxycyclopropyl)glycine-1 (L...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1996.76.4.2808
更新日期:1996-10-01 00:00:00
abstract::1. Teased axon recordings were made from 167 spontaneously active A beta- and A delta-afferents that ended in sciatic nerve end neuromas of 6-12 days standing. When challenged with a standard bolus of systemically applied adrenaline, 100 (60%) responded, either with an increase in baseline firing frequency (excitation...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1996.76.6.3721
更新日期:1996-12-01 00:00:00
abstract::Experience-dependent modification in the electrical properties of central neurons is a form of intrinsic plasticity that occurs during development and has been observed following behavioral learning. We report a novel form of intrinsic plasticity in hippocampal CA1 pyramidal neurons mediated by the KV7/KCNQ and CaV1/L...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.90346.2008
更新日期:2008-10-01 00:00:00
abstract::1. Presynaptic activity of identified primary afferents from flexor, extensor, and bifunctional hindlimb muscles was studied with intra-axonal recordings during fictive locomotion. Fictive locomotion appeared spontaneously in decorticate cats (n = 9), with stimulation of the mesencephalic locomotor region (n = 4), and...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.1991.65.4.914
更新日期:1991-04-01 00:00:00
abstract::While the effects of sensory feedback on bimanual tasks have been studied extensively at two ends of the motor control hierarchy, the cortical and behavioral levels, much less is known about how it affects the intermediate levels, including neural control of homologous muscle groups. We investigated the effects of som...
journal_title:Journal of neurophysiology
pub_type: 杂志文章
doi:10.1152/jn.00269.2016
更新日期:2017-02-01 00:00:00