Expression of cocaine- and amphetamine-regulated transcript in the rat forebrain during postnatal development

Area of Science:

• Neuroscience
• Developmental Biology
• Molecular Psychiatry

Background:

• Cocaine- and amphetamine-regulated transcript (CART) is a neuropeptide widely distributed in the rodent brain.
• CART has been linked to various functions, including reward, feeding, stress, sensory processing, and learning.
• Emerging evidence suggests CART's involvement in neural development.

Purpose of the Study:

• To investigate the temporal and spatial distribution of CART mRNA expression in the male and female rat forebrain during postnatal development.
• To compare CART mRNA levels across different developmental stages (P06, P26, P66) and sexes.

Main Methods:

• Quantitative analysis of CART mRNA expression using in situ hybridization.
• Examination of forebrain tissue from male and female Sprague-Dawley rats at postnatal days 6, 26, and 66.

Main Results:

• At P06, significant CART mRNA expression was observed in the somatosensory cortex, piriform cortex, indusium griseum, dentate gyrus, nucleus accumbens, ventral premammillary nucleus, and notably, the ventral posteromedial and posterolateral thalamic nuclei.
• Thalamic CART mRNA expression was transient, present only at P06 and absent at later stages.
• CART mRNA levels were decreased in the arcuate nucleus at P06 and increased in the anteroventral periventricular nucleus of adult females, with no significant differences in other examined regions across ages and sexes.

Conclusions:

• CART gene expression exhibits dynamic temporal and spatial regulation in the developing rat forebrain.
• The findings suggest that CART peptides are involved in the development of neural circuits critical for sensory processing, reward, and memory formation.