Electrophysiological and morphological properties of neurons acutely isolated from the rostral gustatory zone of the rat nucleus of the solitary tract

The biophysical and morphological characteristics of acutely isolated neurons from the rostral nucleus of the solitary tract (rNST) were investigated under current clamp conditions and compared with the results obtained from neurons recorded in brain slices. The passive membrane properties of the isolated neurons were similar to rNST neurons in brain slices and the neurons maintained their morphological characteristics although their dendritic tree was truncated. The isolated neurons also retained their characteristic repetitive firing properties. In addition we also noted developmental changes in the intrinsic membrane properties of the isolated neurons, such as a shortening in action potential duration, decrease in membrane time constant and input resistance, that occurred when these parameters were compared in neurons isolated from young (5-10 days) and older animals. These enzymatically dispersed neurons therefore retained both the membrane properties and morphology observed in the intact brainstem and in vitro brain slice preparation. The use of this isolated neuron preparation provides a basis for further study of rNST neurobiology.