Differential Behavioral Responses to\ud Cocaethylene of Long-Evans and\ud Sprague-Dawley Rats: Role of Serotonin

Cocaethylene is a neuroactive metabolite derived from the concurrent consumption of cocaine and ethanol. The effects of cocaethylene on locomotor activity, stereotypy, and rearing in Long-Evans and Sprague-Dawley rats were compared.A single cocaine injection (molar equivalent of 60 μmol/kg cocaethylene, intraperitoneal) elicited a robust series of motor output behaviors, including locomotion, stereotypy, and rearing over a 30-minute testing period in Long-Evans rats. In contrast, cocaethylene administration,\ud under comparable testing conditions, produced no significant changes in locomotor and investigatory behaviors. Because cocaethylene has relatively little impact on serotonin (5-HT) reuptake as opposed to reuptake of dopamine, we pretreated Long-Evans rats with fluoxetine (10 mg/kg; IP), a selective 5-HT reuptake inhibitor. Fluoxetine profoundly augmented cocaethylene-stimulated behaviors in this rat phenotype. To examine whether other rat strains exhibit a similar response to cocaethylene, Sprague-Dawley rats were injected (IP) with cocaethylene and their behavior patterns monitored over a 30-minute testing period. Cocaethylene produced marked locomotor and exploratory behaviors in this strain, suggesting therefore that Long-Evans and Sprague-\ud Dawley rats differ in their response to cocaethylene. To relate these behavioral differences to possible structural differences in the neuronal density of dopaminergic or\ud serotonergic neurons, Long-Evans and Sprague-Dawley brains were evaluated for tyrosine hydroxylase and 5-HT immunocytochemistry. No gross morphological differences\ud in neuronal architecture or density were found in the ventral tegmental area or dorsal raphe nucleus of the two rat phenotypes. These results indicate that two commonly used rat strains show a differential response to cocaethylene and the neurochemical basis for this behavioral difference may be related to synaptic 5-HT bioavailability

Effects of cocaethylene on dopamine and serotonin synthesis in Long–Evans and Sprague–Dawley brains

We examined the behavioral and neurochemical effects of cocaethylene treatment in Long–Evans (�LE). and Sprague–Dawley� (SD) rats. Cocaethylene-induced behaviors were significantly less in LE rats. Cocaethylene caused an inhibition of dopamine synthesis in the caudate nucleus and nucleus accumbens that was equivalent in both rat lines. Serotonin synthesis was also suppressed by cocaethylene treatment, however this phenomenon was less pronounced when compared with the effects on dopamine synthesis

Dopaminergic, glutamatergic but not opioidergic mechanisms mediate induction of FOS-like protein by cocaethylene

Cocaethylene is a psychoactive metabolite formed\ud during the combined consumption of cocaine and ethanol. As\ud this metabolite has many properties in common with cocaine, it is conceivable that cocaethylene administration may induce the activity of nuclear transcription factors that regulate the expression of late-response genes. Therefore, the temporal induction of FOS-like protein in rat brain was examined following IP administration of 60 mmol/kg cocaethylene. Immunoreactivity for the protein was detectable at 1 h in striatal neurons and had virtually disappeared 6 h after drug treatment. Administration of\ud specific dopaminergic (SCH-23390; 0.5 mg/kg) and glutamatergic (MK-801; 1 mg/kg) receptor antagonists prior to cocaethylene indicated a significant role for dopamine (D1) and Nmethyl-D-aspartate receptor subtypes in mediating the nuclear induction of the aforementioned transcription factor protein. In contrast, no significant effects on FOS-like protein in discrete neurons of the caudate putamen were found when spiradoline (U-62066), a kappa opioid-receptor agonist, was administered either IP (10 mg/kg) or directly (50 nmol) into the brain parenchyma. In addition, we uncovered a differential sensitivity of Long–Evans rats to the behavioral effects of cocaethylene, with the psychoactive metabolite producing significantly less behavioral activity (e.g., locomotion, rearing, and continuous sniffing)than that produced by cocaine (molar equivalent of 60 mmol/kg cocaethylene). These findings indicate both common and disparate effects of cocaethylene and its parent compound, cocaine, on receptor pathways that regulate target alterations in gene expression and drug-induced motor behavior

Perinatal maternal and neonatal behaviour in the captive reticulated giraffe

A captive reticulated giraffe was observed constantly for three weeks prior to, and periodically for 90 days subsequent to, the birth of her calf. Extensive observations were made of the birth sequence, feeding, drinking, sleeping and one instance of an infant distress call, as well as observations of the initiation of maternal behaviour (including licking, nursing, placentophagia, and what appeared to be helping the calf to stand, guiding the calf's movements, and attempts to respond to the calf's distress call).'n Kameelperdkoei in gevangeskap is onafgebroke vir drie weke voor en periodiek vir 90 dae na die geboorte van haar kalf dopgehou. Noukeurige waarnemings is gedoen van die geboorteproses, die voeding, soog, slaap en, op een geleentheid, van die noodroep van die kalf. Verdere waarnemings is ook gedoen ten opsigte van die aanvang van moedergedrag insluitend die lek en oppas van die kalf, verwydering van die plasente, optrede wat voorgekom het as hulp aan die kalf om te staan, stuur van die kalf in sy bewegings en reaksie op die noodroep van die kalf

Note on sleep in captive giraffes (Giraffa Camelopardalis Reticulata)

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