1. The behavioral tractability of the rabbit was exploited and enabled, in fully awake state, receptive-field analysis antidromically identified efferent neurons within vibrissa representation primary somatosensory cortex (S-1). Efferent studied included ipsilateral corticocortical (C-IC neurons, n = 56) that project to or beyond second cortical area (S-2) corticofugal layer 5 (CF-5 75) 6 (CF-6 92) and/or thalamus. 2. An additional class not activated from any stimulus site, but which...

Thalamocortical (TC) impulses potently influence the sensory neocortex, but functional impact of individual TC neurons throughout layers cortex has proved difficult to assess. Here we examine, in awake rabbits, vertical distribution monosynaptic currents generated a somatosensory cortical "barrel" column by spontaneous single, topographically aligned neurons. We show that closely neighboring generate widely differing patterns activation within 4 and 6 their column. Moreover, synaptic with...

Swadlow, Harvey A., Irina N. Beloozerova, and Mikhail G. Sirota. Sharp, local synchrony among putative feed-forward inhibitory interneurons of rabbit somatosensory cortex. J. Neurophysiol. 79: 567–582, 1998. Many suspected (SINs) primary cortex (S1) receive a potent monosynaptic thalamic input (thalamocortical SINs, SINstc). It has been proposed that nearly all such SINstc S1 barrel column (BC) excitatory synaptic from each member subpopulation neurons within the topographically aligned...

1. Properties of antidromically identified efferent neurons within the cortical representation vibrissae, sinus hairs, and philtrum were examined in motor cortex fully awake adult rabbits. Efferent tested for both receptive field axonal properties included callosal (CC) (n = 31), ipsilateral corticocortical (C-IC) 34) that project to primary somatosensory (S-1), corticofugal layer 5 (CF-5) 33) 6 (CF-6) 32) and/or beyond thalamus. Appropriate collision tests demonstrated substantial numbers...

This study examines the activity of different classes neurons motor cortex in rabbit during two locomotion tasks: a simple (on flat surface) and complex (overstepping series barriers) locomotion. Four efferent were studied: corticocortical (CC) with ipsilateral projection (CCIs), those contralateral (CCCs), descending corticofugal layer V (CF5s), VI (CF6s). In addition, one class inhibitory interneurons (SINs) was investigated. CF5 SINs only groups that strongly active most these clear-cut...

1. Responses of thalamocortical projection neurons and suspected cortical interneurons (SINs) to very brief peripheral stimuli were examined within the vibrissae, sinus hair, lip, chin representations ventroposterior medial thalamus (VPM) primary somatosensory cortex (S1). VPM (N = 40) identified by their antidromic activation after electrical stimulation S1. SINs a high-frequency (> 600 Hz) burst three or more spikes elicited suprathreshold one afferent pathways. also had short duration....

The long-term stability of conduction velocity and recovery processes were studied in a fast-conducting (corticotectal) more slowly conducting (visual callosal) axonal system. Chronic microelectrode recording methods used conjunction with antidromic activation via electrical stimulation at one or site. These enabled 54 axons to be for greater than 20 days seven these cells 101-448 days. velocities corticotectal characteristic myelinated very stable over time. most callosal nonmyelinated...

Several efferent systems of visual area I in Dutch rabbits were studied with anatomical (horseradish peroxidase) and physiological (antidromic) methods. Anatomical studies provided information regarding the laminar origin projections to contralateral hemisphere, II, dorsal lateral geniculate nucleus, superior colliculus. Physiological conduction velocities multiple destinations axons. Both callosal projection V-II shown originate primarily layer II-III. However, approximately 10-20% 20-40%...

ON and OFF visual pathways originate in the retina at synapse between photoreceptor bipolar cells. cells are shorter length use receptors with faster kinetics than and, therefore, process information faster. Here, we demonstrate that this temporal advantage is maintained through thalamocortical processing, responses reaching cortex ~3-6 ms before responses. Faster could be demonstrated recordings from large populations of cat thalamic neurons representing center vision (both X Y)...

The dorsal side-up body orientation in quadrupeds is maintained by a postural system that driven sensory feedback signals. spinal cord, brainstem, and cerebellum play essential roles control, whereas the role of forebrain unclear. In present study we investigated whether motor cortex involved maintenance orientation. We recorded activity neurons awake rabbits while animals balance on platform periodically tilting frontal plane. tilts evoked corrections, i.e., extension limbs side moving down...

The intrinsic stability of the rabbit eye was exploited to enable receptive-field analysis antidromically identified corticotectal (CT) neurons (n = 101) and corticogeniculate (CG) 124) in visual area I awake rabbits. Eye position monitored within 1/5 degrees. We also studied properties synaptically activated via electrical stimulation dorsal lateral geniculate nucleus (LGNd). Whereas most CT had either complex (59%) or motion/uniform (15%) receptive fields, we found with simple (9%)...

Abstract The connections of cingulate cortex with visual, motor, and parahippocampal cortices in the rabbit brain are evaluated by using a modified Brodmann cytoarchitectural scheme, electrophysiological mapping techniques, pathway tracers horseradish peroxidase (HRP) tritiated amino acids. Rabbit can be divided into areas 25, 24, 29. Area 29 isof particular interest because area 29d has lateral extension granular layer IV, 29b caudal which differ from anterior 29b, there is prominent 29e....

1. In fully awake rabbits the stability of two eyes was monitored and sufficient to enable receptive-field analysis antidromically identified efferent neurons suspected interneurons in binocular segment visual area Efferent analyzed included callosal (CC neurons, n = 52), projecting 2 (CV2 35), corticotectal (CT 43), corticogeniculate (CG 51). Six additional projected a branching axon both corpus callosum 2. Most CC CV2 were found layer 2-3 had receptive fields simple type. Only...