The role of inhibitory processes in the formation of functional properties of neurons in vibrissal projection zone of the cat somatosensory cortex

Abstract

The role of intracortical inhibitory processes in the formation of neuronal receptive fields in the vibrissal projection zone of the somatosensory cortex was studied. Iontophoretic application of picrotoxin and bicuculline blocks the inhibition and causes the loss of directional sensitivity in neurons. Activation of inhibition by distant glutamate application gives opposite results--neurons become direction sensitive. A dependence was found between spatial location of activated cells and the pattern of changes of their detector properties. Inhibitory processes caused by natural afferent stimulation lead to similar changes in the functional properties of neurons.

Study of the cortical representation of whisker directional deflection using voltage-sensitive dye optical imaging

“…Our obtained optical imaging data correspond to electrophysiological data obtained previously by many authors Moore, 2006, 2008;Batuev et al, 1989). The strong compliance between the arrangement of the centers of mass of the patterns activated by different stimuli, and disposition of these stimuli permits us to draw a conclusion about the functional representation of angular selectivity in the somatosensory cortex.…”

“…According to the results of numerous studies Moore, 2006, 2008;Batuev et al, 1989;Furuta et al, 2009;Khatri and Simons, 2007), neurons of the rat barrel field are sensitive to the angular direction of whisker movement. Our obtained optical imaging data correspond to electrophysiological data obtained previously by many authors Moore, 2006, 2008;Batuev et al, 1989).…”

Functional organization of tactile inputs from the hand in the cuneate nucleus and its relationship to organization in the somatosensory cortex

“…On the basis of the cascading nature of these excitatory connections, one might expect area 3b fields to be larger than CN fields. However, excitatory convergence/divergence is constrained by sharpening mechanisms that involve inhibition (e.g., Dykes et al, 1984;Hicks et al, 1986;Batuev et al, 1989;Alloway and Burton, 1991;Willis and Coggeshall, 1991;Rausell et al, 1992b;Jones, 1993;Lee et al, 1994;Kyriazi et al, 1996;Ralston et al, 1996;Dykes and Craig, 1998) and, probably, excitatory feedback amplification (e.g., Somers et al, 1995). The relative contributions that sharpening versus excitatory convergence/divergence make to field sizes remain unclear.…”

Intrinsic optical imaging of directional selectivity in rat barrel cortex: Application of a multidirectional magnetic whisker stimulator

“…In contrast to the visual and auditory cortices (Kalatsky et al, 2005;Kral et al, 2003;Tsytsarev et al, 2004), however, organization of the rat barrel cortex has not been proven to have significant directional sensitivity. Following a suggestive earlier study (Batuev et al, 1989), and evidence of directional sensitivity was obtained (Li and Ebner, 2007), another group (Andermann and Moore, 2006) provided electrophysiological evidence that the barrel cortex exhibits somatotopically organized directional sensitivity, and may indeed be as sensitive to direction as the highly-developed visual and auditory cortices (Imamura et al, 2006;Tsytsarev et al, 2004). This sensitivity might be of particular importance to the rat, whose visual system is not as highly developed as that of many other mammals, such as cats, which have exquisitely complex orientation sensitivity in their visual cortices.…”