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Serotonin 2A and 2C receptor biosynthesis in the rodent striatum during postnatal development: mRNA expression and functional linkage to neuropeptide gene regulation
Author(s) -
Basura Gregory J.,
Walker Paul D.
Publication year - 2000
Publication title -
synapse
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.809
H-Index - 106
eISSN - 1098-2396
pISSN - 0887-4476
DOI - 10.1002/1098-2396(200011)38:2<216::aid-syn12>3.0.co;2-5
Subject(s) - medicine , endocrinology , striatum , serotonin , receptor , biology , neuropeptide , gene expression , neuropeptide y receptor , messenger rna , in situ hybridization , 5 ht receptor , gene , dopamine , biochemistry
The present study was designed to determine if there are region‐specific differences in serotonin (5‐HT) neurotransmission and 5‐HT receptor expression that may limit the stimulatory effects of the 5‐HT releaser p ‐chloroamphetamine ( p CA) on striatal neuropeptide gene expression to the posterior striatum (P‐STR) during postnatal maturation. Sprague‐Dawley rat brains from postnatal days (PND) 1–35 were processed for 5‐HT 2A and 5‐HT 2C receptor mRNA expression by in situ hybridization and monoamine analysis by HPLC. Within the P‐STR, 5‐HT 2A receptor mRNA expression reached young adult (PND 35) levels by PND 3, while levels in the A‐STR were significantly less (range: 1.43 ± 0.219–6.36 ± 0.478) than P‐STR (5.36 ± 0.854–12.11 ± 1.08) at each respective age throughout the time course. 5‐HT 2C receptor mRNA expression reached young adult levels at PND 7 in the A‐STR and by PND 3 in the P‐STR. At each PND age 5‐HT 2C receptor mRNA levels within the P‐STR were significantly less (6.23 ± 1.02–12.32 ± 0.427) than the A‐STR (7.31 ± 1.65–26.84 ± 2.24). 5‐HT content increased across the developmental time course within the P‐STR (5.01 ± 0.327–15.7 ± 1.03 ng/mg protein) and A‐STR (2.97 ± 0.223–11.2 ± 0.701 ng/mg protein). Four hours following injection (i.p.) of p CA (10 mg/kg), preprotachykinin (PPT) mRNA levels increased 89% in the P‐STR but not the anterior (A‐STR) striatum of the 3‐week‐old rat, which were prevented by preinjection (30 min, i.p.) of the 5‐HT 2 receptor antagonist ritanserin (1 mg/kg). Together, these data suggest that faster maturity of 5‐HT 2A receptor expression in the P‐STR may be sufficient to convey the region‐specific acute stimulatory effects of p CA on PPT mRNA transcription in the developing rodent striatum. These results provide further evidence that the influence of 5‐HT on neuropeptide gene expression is far stronger in caudal vs. rostral striatal regions during postnatal development. Synapse 38:216–225, 2000. © 2000 Wiley‐Liss, Inc.