Connections of latero-dorsal nucleus of the thalamus. II. Experimental study in Papio papio.
Modifications of the latero-dorsal (L.D.) nucleus of the thalamus have been observed earlier in man in relation to limbic lesion of various etiologies. Our proposal was to determine the role of L.D. in memory disturbances. We attempted to study the connections of L.D. in Papio papio baboon after surgical lesion using silver impregnations as well as traditional techniques. We found three afferent pathways: from the fornix, the posterior cingulate and the parietal cortex (area 7). The most important is the afferent system from the fornix, it terminates in the antero-dorso-medial part of L.D.; the other two afferent pathways have a postero-lateral projection in L.D. The three efferent systems to parietal cortex, cingulate and fornix were not delineated in this study. It was concluded that the antero-dorso-medial portion of L.D. is connected to the limbic system and the ventro-postero-lateral portion integrated into a large parieto-cingulo-parahippocampal circuit to which it is joined by direct and indirect projections with several relays. These connections have important implications, perhaps, in our understanding of memory disturbances.
D000344:Afferent Pathways / Q000166:cytology; D000818:Animals; D006179:Gyrus Cinguli / Q000166:cytology*; D000882:Haplorhini; D006624:Hippocampus / Q000166:cytology*; D006801:Humans; D008569:Memory Disorders / Q000473:pathology; D010215:Papio; D010296:Parietal Lobe / Q000166:cytology*; D013787:Thalamic Nuclei / Q000166:cytology*