Sep 1, 1989

Thalamic and extrathalamic connections of the dysgranular unresponsive zone in the grey squirrel (Sciurus carolinensis)

The Journal of Comparative Neurology
H J GouldM S LeDoux


The connections of the cortical dysgranular "unresponsive zone" (UZ) (Sur et al.: J. Comp. Neurol. 179:425-450, '78) in the grey squirrel were studied with horseradish peroxidase and autoradiographic techniques. The results of these experiments show that the major subcortical connections of the unresponsive zone are in large part reciprocal. Connections are distributed within the thalamus in a poorly defined region including restricted portions of several nuclei that lie along the rostral, dorsal, and caudal borders of the ventral posterior nucleus. Additional thalamic connections of the UZ terminate in the reticular nucleus and are reciprocally related to the paralaminar and central median nuclei. Extrathalamic terminations were observed in the zona incerta, the intermediate and deep layers of the superior colliculus, the red nucleus, and several subdivisions of the pontine nuclei. The similarity between the pattern of subcortical connections of the UZ in the grey squirrel and patterns reported for the parietal septal region in rats (Chapin and Lin: J. Comp. Neurol. 229:199-213, '84) and for area 3a in primates (Friedman and Jones: J. Neurophysiol. 45:59-85, '81), suggests that the UZ in the grey squirrel may represent a count...Continue Reading

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  • Citations8


Mentioned in this Paper

Biochemical Pathway
Entire Red Nucleus
Cortex Bone Disorders
Adrenal Cortex Diseases
Genus Saimiri
Sciurus carolinensis
Wheat Germ Agglutinin Isolectin 2
Structure of Zona Incerta

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