Paleostriatum: A pale-appearing spherical area in the brain. The paleostriatum is specifically part of what is called the lentiform nucleus which, in turn, is part of the striate body, a component of the basal ganglia, large masses of gray matter at the base of the cerebral hemispheres of the brain.
Cells within the paleostriatum may be preferentially damaged and perish in carbon monoxide poisoning, barbiturate intoxication, cyanide poisoning, hydrogen sulfide poisoning, profound prolonged hypoglycemia, hypoxia, hypotension, and Wilson disease.
Paleostriatum means old stratum. It was so named because it was thought to have evolved before the neostriatum (the new stratum), a different part of the striate body of the brain.