We immunohistochemically characterised the expression of the calcium-bindin
g protein parvalbumin in the normal human anteroventral thalamic nucleus (A
VN). Two morphologically distinct neuronal populations were found to be par
valbumin-immunoreactive (PV-IR): a large population of lightly staining PV-
IR neurons and a smaller population of intensely PV-IR neurons. This second
type of neuron, which displayed many characteristics normally associated w
ith GABAergic interneurons, has nor previously been described in human thal
amus. Thus, presumptive thalamic interneurons in the human brain can be fur
ther subtyped on the basis of immunoreactivity to parvalbumin. This may hav
e implications for the understanding of thalamocortical function in the nor
mal state and in dysfunctional conditions such as Wernicke-Korsakoff syndro
me and schizophrenia. NeuroReport 11:97-101 (C) 2000 Lippincott Williams &
Wilkins.