The total number of neurons and calcium binding protein positive neurons during aging in the cochlear nucleus of CBA/CaJ mice: a quantitative study

• Published in: Hearing research Vol. 158; no. 1; pp. 102 - 115
• Main Authors: Idrizbegovic, E, Canlon, B, Bross, L.S, Willott, J.F, Bogdanovic, N
• Format: Journal Article
• Language: English
• Published: Amsterdam Elsevier B.V 01.08.2001; Elsevier
• Subjects: Aging - metabolism; Animals; Auditory; Biological and medical sciences; Calbindin; Calbindin 1; Calbindin 2; Calbindins; Calcium-Binding Proteins - metabolism; Calretinin; Cell Count; Cochlear Nucleus - cytology; Cochlear Nucleus - metabolism; Ear and associated structures. Auditory pathways and centers. Hearing. Vocal organ. Phonation. Sound production. Echolocation; Female; Fundamental and applied biological sciences. Psychology; Male; Medicin och hälsovetenskap; Mice; Mice, Inbred CBA; Neurons - cytology; Neurons - metabolism; Optical fractionator; Parvalbumin; Parvalbumins - metabolism; S100 Calcium Binding Protein G - metabolism; Stereology; Tissue Distribution; Vertebrates: nervous system and sense organs; Calbindin; Stereology; Auditory; Calretinin; Parvalbumin; Optical fractionator; Senescence; Dorsal cochlear nucleus; Calcium; Rodentia; Central nervous system; Ventral cochlear nucleus; Binding protein; Vertebrata; Mammalia; Mouse; Auditory pathway; Age; Brain (vertebrata)
• ISSN: 0378-5955; 1878-5891
• DOI: 10.1016/S0378-5955(01)00295-7

The quantitative stereological method, the optical fractionator, was used for determining the total number of neurons and the total number of neurons immunostained with parvalbumin, calbindin-D28k (calbindin), and calretinin in the dorsal and posteroventral cochlear nucleus (DCN and PVCN) in CBA/CaJ (CBA) mice during aging (1–39 months old). CBA mice have only a modest sensorineural pathology late in life. An age-related decrease of the total number of neurons was demonstrated in the DCN ( r=−0.54, P<0.03), while the total number of neurons in the PVCN did not show any significant age-related differences ( r=0.16, P=0.57). In the DCN 5.5% of neurons were parvalbumin positive in the very old (30–39 months) mice, vs. 2.2% in the 1 month old mice. In the DCN 3% of the neurons were calbindin immunopositive in the 30–39 months mice compared to 1.9% in the 1 month old group. In the PVCN, 20% of the neurons in the very old mice were parvalbumin immunopositive, compared to 12% in the young mice. Calbindin did not show any significant age-related differences in the PVCN. The total number of calretinin immunopositive neurons both in the DCN and PVCN did not show any significant change with increasing age. In conclusion, the total neuronal number in the DCN and PVCN was age-related and region-specific. While the neuronal number in the DCN and PVCN was decreased or unchanged, respectively, the calcium binding protein positive neuronal number showed a graded increase during aging in a region-specific and protein-specific manner.