Receptive field

About: Receptive field is a research topic. Over the lifetime, 8537 publications have been published within this topic receiving 596428 citations.

Decreased activity of spontaneous and noxiously evoked dorsal horn cells during transcutaneous electrical nerve stimulation (TENS)

Abstract: The purpose of this study was to examine the effects of TENS application to somatic receptive fields on spontaneous and noxiously evoked dorsal horn cell activity in α-chloralose-anesthetized cat. Carbon-filament microelectrodes were used to record extracellular action potentials from 83 spontaneously discharging cells. Using a commercial TENS unit (Medtronic Eclipse Model 7723), spontaneous cell activity was decreased in 54% (65%) of the cells. Twenty-five (30%) did not respond and 4 (5%) increased activity. It was also shown that for 36 cells which were evoked with either manual pinch (19 cells) or manual clamp (17 cells), cell activity decreased during TENS application. This study shows that dorsal horn neurons which can potentially transmit noxious information to supraspinal levels, can have their cell activity decreased during TENS application to somatic receptive fields. This is consistent with the concept of the ‘gate control theory of pain’ in that less noxious information would be involved in the pain perception process.

Quantitative measurements of receptive field changes during antagonism of GABAergic transmission in primary somatosensory cortex of cats.

Abstract: In cortical area 3b of cats, responses of 76 single neurons to punctate indentations were recorded before and during iontophoretic administration of bicuculline methiodide (BMI), a GABAergic antagonist, at levels that did not affect spontaneous activity. Constant amplitude indentations were applied to selected sites along distalproximal and radial-ulnar axes that intersected the most sensitive area in the receptive field. Profiles of response magnitudes were used to measure receptive field dimensions before and during antagonism of GABAergic inhibition. Blockade of GABAergic transmission caused receptive field dimensions of 48 rapidly-adapting neurons to increase an average 141%, or nearly 2.5 times their original size. Analysis of the spatial distribution of inhibition indicated that in-field inhibition was larger than surround inhibition. During BMI administration, response latency was significantly longer for response elicited from the expanded territory than for responses elicited from within the original receptive field, suggesting that receptive field expansion might be mediated by multisynaptic intracortical connections. The magnitude of receptive field expansion was independent of receptive field size or peripheral location. In a substantial number of neurons, however, BMI produced asymmetric expansions that extended only in the proximal direction. For 9 slowly-adapting neurons, BMI produced measureable increases in receptive field dimensions, but these changes were significantly smaller than the changes in rapidly-adapting neurons.

Cholinergic modulation of responses to single tones produces tone-specific receptive field alterations in cat auditory cortex.

Abstract: Acetylcholine (ACh), acting via muscarinic receptors, is known to modu- late neuronal responsiveness in primary sensory neocortex. The administration of ACh to cortical neurons facilitates or suppresses responses to sensory stimuli, and these effects can endure well beyond the period of ACh application. In the present study, we sought to determine whether ACh produces a general change in sensory information processing, or whether it can specifically alter the processing of sensory stimuli with which it was "paired." To answer this question, we restricted acoustic stimulation in the presence of ACh to a single frequency, and determined single neuron frequency receptive fields in primary auditory cortex before and after this pairing. During its administration, ACh produced mostly facilitatory effects on spontaneous activity and on responses to the single frequency tone. Examination of frequency receptive fields after ACh administration revealed receptive field modifications in 56% of the cells. In half of these cases, the receptive field alterations were highly specific to the frequency of the tone previously paired with ACh. Thus ACh can produce stimulus-specific modulation of auditory information processing. An additional and unexpected finding was that the type of modulation during ACh administration did not predict the type of receptive field modulation observed after ACh administration; this may be related to the physiological "context" of the same stimulus in two different conditions. The implications of these findings for learning-induced plasticity in the auditory cortex is discussed.