Effects of postnatal undernutrition on the catecholamine and serotonin contents of suckling rat brain.

Abstract

SummaryThe effect of postnatal undernutrition on the catecholamine and serotonin contents of various parts of the brain of suckling rats was examined. Undernourishment was induced by increasing the litter size to 18 pups from day 1 to 21 after birth. In control pups, the total amounts of norepinephrine and dopamine in the whole brain increased greatly during the suckling period (norepinephrine: 17.7ng at birth, 154ng on day 10, and 420ng on day 21; dopamine: 12.6ng at birth, 269ng on day 10, and 1,022ng on day 21). Similar, but less marked increases in the norepinephrine and dopamine contents of the brain were observed in malnourished pups. The norepinephrine contents of the forebrain, cerebellum, and brain stem of malnourished pups were comparable with those of normal pups on day 10 but the contents of the cerebellum and brain stem were significantly less than those of normal pups on day 21. Postnatal malnutrition also led to a significant decrease in the dopamine content of the forebrain. In contrast, the serotonin content of the brain of undernourished pups was significantly higher than that of controls. The activities of tyrosine hydroxylase in the forebrain and brain stem of control pups at the end of suckling period were significantly higher than those of undernourished pups (forebrain: 18.3pmol in controls and 11.5 pmol in malnourished pups; brain stem: 12.3pmol in controls and 9.8 pmol in malnourished pups). The tyrosine hydroxylase activity (pmol/g) correlated more closely with the norepinephrine content than with the dopamine or norepinephrine plus dopamine content. The tyrosine and phenylalanine contents of the brain were similar in the two groups. It is concluded from these findings that the catecholamine content of the brain is regulated by the enzyme activity rather than the levels of precursor amino acids. Keywords brain catecholamine (CA), serotonin, tyrosine hydroxylase, early postnatal malnutrition, lactation, brain free amino acids 279

Neonatal phencyclidine treatment selectively attenuates mesolimbic dopamine function in adult rats as revealed by methamphetamine-induced behavior andc-fos mRNA expression in the brain

“…Facchinetti et al (1993) demonstrated that prolonged neonatal treatment (PD 1-22) of the NMDA receptor through a noncompetitive (MK-801) or competitive (CGP 39551) antagonist increased spontaneous locomotor activity on PD 28 and this increase continued to PD 60. Neonatal malnutrition can affect the neurochemical markers of dopaminergic function in the brain, such as dopamine content or tyrosine hydroxylase activity (Hisatomi and Niiyama, 1980;Ramanamurthy, 1977;Sobotka et al, 1974). Their findings were in contrast with those of our behavioral study, in which neonatal PCP reduced MAP-induced stereotyped behavior.…”

Undernutrition and Overnutrition in the Neonatal Rat: Long-Term Effects on Noradrenergic Pathways in Brain Regions

“…However, studies of central catecholaminergic mechanisms suggest that abnormal nutritional status has a substantial deleterious effect on neuronal and synaptic function. During dietary restriction, norepinephrine levels and some indices of neuronal activity show moderate degrees of attenuation (4)(5)(6)(7)(8); although whole brain norepinephrine levels tend to be restored to normal in adulthood (9-1 I), there are at least two reports that deficits in receptor binding sites and synaptic activity may persist if malnutrition is maintained into adulthood (12,13).…”

Enhanced Behavioral Response to Serotonin-Related Agonists in Postweaning Protein Malnourished Mice

“…While most studies have found an increase in serotonin concentration [23][24][25][26][27] others have reported a decrease or no change in undernourished rodents or humans. 11,12,28,29) In addition, previous studies have shown that PM causes a reduction in 5-HT 1A binding 12) and hyporeactivity to 5-HT 1A receptor agonists.…”

“…Although the influence of early postnatal undernutrition on the serotonergic systems has been the subject of considerable biochemical research, [23][24][25] the data on brain serotonin content in early undernourishment is conflicting. While most studies have found an increase in serotonin concentration [23][24][25][26][27] others have reported a decrease or no change in undernourished rodents or humans.…”

“…Recently it has become apparent that brain development continues through adolescence and that prepubescence represents a period sensitive to nutritional deficits, 42) drug abuse 43) and isolation rearing. 44) In the rat, some brain structures, such as the hippocampus, are not even fully developed until as late as postnatal days 35-40. 45) Majority (85%) of the granule cells of the dentate gyrus are generated postnatally with the greatest cell proliferation between postnatal days [20][21][22][23][24][25][26][27][28][29][30]46) and may continue to be generated well into adult life. [47][48][49] Similarly, neurotransmitter levels (noradrenaline, dopamine and 5-HT) continue to develop postnatally, reaching adult levels between 30-50 d of age.…”