Neurotrophin-like immunoreactivity in the human hippocampal formation

The immunohistochemical occurrence and localisation of the neurotrophins ne rve growth factor, brain-derived neurotrophic factor (BDNF), neurotrophin-4 , and neurotrophin-3 is described in the human post-mortem hippocampal form ation from subjects aged 23 weeks of gestation to 68 years. Labeled neurona l cell bodies and processes were detectable for each neurotrophin at all ex amined ages with age-related changes in their distribution pattern. As a ge neral rule, a higher number of immunoreactive perikarya was found in subjec ts at pre- and perinatal ages than in adults. At variance with the other ne urotrophins, the BDNF antiserum labelled also extensive nerve fibre systems , whose occurrence and distribution widened with age. The results obtained provide a morphological ground in support to the concept that the neurotrop hins play a functional role in the human hippocampal circuitry throughout l ife. (C) 1999 Elsevier Science Inc.