Extrathalamic ascending projections to physiologically identified fields of the cat auditory cortex

• Published in: Hearing research Vol. 40; no. 3; pp. 233 - 246
• Main Authors: Rouiller, E.M, Hornung, J.P, De Ribaupierre, F
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.07.1989; Elsevier
• Subjects: Acetylcholine - metabolism; Animals; Auditory cortex; Auditory Cortex - cytology; Auditory Cortex - metabolism; Auditory Pathways - anatomy & histology; Biological and medical sciences; Brain - anatomy & histology; Brain - metabolism; Cat; Catecholamines - metabolism; Cats; Claustrum; Cortical inputs; Ear and associated structures. Auditory pathways and centers. Hearing. Vocal organ. Phonation. Sound production. Echolocation; Fundamental and applied biological sciences. Psychology; gamma-Aminobutyric Acid - metabolism; Hearing; Horseradish Peroxidase; Immunohistochemistry; Lateral hypothalamus; Neurons, Afferent - cytology; Neurons, Afferent - metabolism; Neurotransmitter Agents - metabolism; Nucleus of the brachium of the inferior colliculus; Vertebrates: nervous system and sense organs; Wheat Germ Agglutinin-Horseradish Peroxidase Conjugate; Wheat Germ Agglutinins; Cortical inputs; Hearing; Nucleus of the brachium of the inferior colliculus; Cat; Lateral hypothalamus; Claustrum; Auditory cortex; Fissipedia; Brain; Carnivora; Vertebrata; Mammalia; Central nervous system; Electrophysiology; Afferent projection
• ISSN: 0378-5955; 1878-5891
• DOI: 10.1016/0378-5955(89)90164-0

The neurons of origin of ascending extrathalarnic projections to the auditory cortex were labeled retrogradely with WGA-HRP injected in physiologically identified auditory cortical fields of the cat (anterior (AAF), primary (AI), posterior (PAF) and secondary (All) fields). After injection in the tonotopically organized auditory cortical fields (AAF, AI and PAF), labeled neurons were distributed in 7 extrathalamic subcortical regions included in one or the other of 2 distinct systems of ascending projections to the neocortex. In the ‘diffuse’ system of projection, labeled neurons were observed bilaterally in the locus coeruleus, the nuclei of the raphe, the lateral hypothalamus, ipsilaterally in the ventromedial mesencephalic tegmentum and the basal forebrain; in the ‘accessory sensory’ system of projection, labeled neurons were found ipsilaterally in the nucleus of the brachium of the inferior colliculus and bilaterally in the claustrum. After injection in AH, labeled neurons were seen only in the ‘diffuse’ system of projection. For AAF and AI, the major contribution to the total extrathalamic ascending input originated from the lateral hypothalamus, whereas for All it was the locus coeruleus. In contrast, PAF received extrathalamic ascending inputs mainly from the claustrum. Anterogradely labeled corticofugal terminal fields were found only in the nucleus of the brachium of the inferior colliculus and, after injection in PAF, in the claustrum.