Laterality and sex differences in the expression of brain-derived neurotrophic factor in developing rat hippocampus

Abstract

Brain-derived neurotrophic factor (BDNF), as a member of neurotrophin family, plays an important role in neurogenesis, neuronal survival and synaptic plasticity. BDNF is strongly expressed in the hippocampus, where has been associated with memory consolidation, learning, and cognition. In this study, Real-time PCR, immunohistochemistry, and stereology were used to evaluate the gender differences and left-right asymmetries in the expression of BDNF in the developing rat hippocampus during the neurogenesis-active period, at postnatal days P0, P7 and P14. We found the lowest expression of BDNF in the right side and the highest in the left side hippocampi of both male and female neonates at P14 (P ≤ 0.05 each). At the same time, there were significant differences in the hippocampal expression of BDNF between males and females (P ≤ 0.05 each). No important differences in the number of BDNF expressing neurons in different subregions of right/left hippocampus were observed between male and female animals at P0 and P7 (P > 0.05). Furthermore, the highest numerical density of BDNF positive cells was detected in the both sides hippocampal CA1 in the male/female offspring at P7, and in the CA2, CA3 and dentate gyrus at P14 (P ≤ 0.05 each). Based on these findings, it can be concluded that there are prominent sex and interhemispheric differences in the expression of BDNF in the developing rat hippocampus, suggesting a probable mechanism for the control of gender and laterality differences in development, structure, and function of the hippocampus.

The Sexual Dimorphic Synapse: From Spine Density to Molecular Composition

“…No difference was found in other regions of the right hippocampus (CA1, CA2, and CA3) or in the left hippocampus. No sex differences in BDNF expression are detectable at earlier points in development (P0 and P7) (Sardar et al, 2021). In humans BDNF was found to be expressed in higher levels in the female frontopolar PFC than in the male one.…”

“…It is known to be differently expressed and involved in sexual dimorphic behaviors. So, the BDNF abundance in the hippocampus, the frontal cortex and the brain stem is higher in male mice over all regions (Szapacs et al, 2004;Sardar et al, 2021). Looking more closely at the hippocampus it was shown that the expression of BDNF in female Sprague-Dawley rats is higher in the CA3 region, lower in the DG and unchanged in the CA1 region compared to males (Franklin and Perrot-Sinal, 2006).…”

Preventive Effect of Limosilactobacillus fermentum SCHY34 on Lead Acetate-Induced Neurological Damage in SD Rats

“…BDNF plays an important role in synapse remodeling in the process of animal learning, memory, and cognition. Combined with its specific receptor tyrosine kinase receptor B (TrkB), it induces phosphorylation at specific sites of the TrkB receptor and transmits BDNF signals to the nucleus for neuroprotection ( 55 ). The immediate-early genes c-fos and c-jun belong to a class of proto-oncogenes which can be induced by second messengers to respond quickly to external stimuli such as neurotransmitters, hormones, and nerve impulses ( 56 ).…”

The Preventive Effect of Lactobacillus Fermentum SCHY34 Isolated from Traditional Fermented Yak Yogurt on Lead Acetate-Induced Neurological Damage in SD Rats

“…Combined with its specific receptor tyrosine kinase receptor B (TrkB), it induces phosphorylation at specific sites of the TrkB receptor and transmits BDNF signals to the nucleus for neuroprotection. [45] The immediate-early genes c-fos and cjun belong to a class of proto-oncogenes which can be induced by second messengers to respond quickly to external stimuli such as neurotransmitters, hormones, and nerve impulses. These genes express their expression products as third messengers to participate in the regulation of the transduction of signals closely related to learning and memory in cells.…”