Chronic sensory deprivation affects cytochrome oxidase staining and glutamic acid decarboxylase immunoreactivity in adult rat ventrobasal thalamus.

The rodent ventrobasal thalamus (VB) contains groups of vibrissa-related neurons (barreloids) that are highly reactive for the enzyme cytochrome oxidase. The present experiments show that each barreloid also contains a dense accumulation of glutamic acid decarboxylase (GAD) immunoreactive terminals. Chronic vibrissa trimming results in parallel declines in staining for both cytochrome oxidase (CO) and GAD in barreloids associated with the trimmed hairs. Thus, thalamic metabolism like that in the cortex is dependent upon normal sensory input. This includes projection neurons as well as neurons in the reticular nucleus, which are the major source of gamma-aminobutyric acid (GABA)ergic input to the rat VB.