Dynamic and multimodal responses of gustatory cortical neurons in awake rats.

Journal Article

To investigate the dynamic aspects of gustatory activity, we recorded the responses of small ensembles of cortical neurons to tastants administered to awake rats. Multiple trials of each tastant were delivered during recordings made in oral somatosensory (SI) and gustatory cortex (GC). When integrated tastant responses (firing rates averaged across 2.5 sec) were compared with water responses, 14.4% (13/90) of the GC neurons responded in a taste-specific manner. When time was considered as a source of information, however, the incidence of taste-specific firing increased: as many as 41% (37/90) of the recorded GC neurons exhibited taste-specific patterns of response. For 17% of the neurons identified as responding with taste-specific patterns, the stimulus that caused the most significant response was a function of the time since stimulus delivery. That is, a single neuron might respond most strongly to one tastant in the first 500 msec of a response and then respond most strongly to another tastant later in the response. Further analysis of the time courses of GC and SI cortical neural responses revealed that modulations of GC firing rate arose from three separable processes: early somatosensory input (less than approximately 0.2 sec post-stimulus), later chemosensory input ( approximately 0.2-1 sec), and delayed somatosensory input related to orofacial responses (more than approximately 1.0 sec). These data demonstrate that sensory information is available in the time course of GC responses and suggest the viability of views of gustatory processing that treat the temporal structure of cortical responses as an integral part of the neural code.

Full Text

Duke Authors

Cited Authors

  • Katz, DB; Simon, SA; Nicolelis, MA

Published Date

  • June 15, 2001

Published In

Volume / Issue

  • 21 / 12

Start / End Page

  • 4478 - 4489

PubMed ID

  • 11404435

Electronic International Standard Serial Number (EISSN)

  • 1529-2401

Language

  • eng

Conference Location

  • United States