Search PubMed⌕ Search

Biomedical subjects

D L Cheney

Publications and source records attributed to D L Cheney.

97 records · Page 6Linked to original sources
PubMedDate not supplied

Levonantradol-induced inhibition of acetylcholine turnover in rat hippocampus and striatum.

The effects of levonantradol, a structural novel cannabinoid-related analgesic, on the turnover rate of acetylcholine (TRACh) have been studied in various regions of the rat brain. Levonantradol (0.3 mg/kg subcutaneously) decreases the tRACh in the hippocampus and striatum by 53 and 30 per cent, respectively. The extent of the reduction in TRACh is dose dependent, with a maximal decrease of 80 per cent in the hippocampus and 57 per cent in the striatum following the 3 mg/kg dose. In contrast, cortical TRACh is not affected by any dose of levonantradol. This pattern of activity on cholinergic dynamics elicited by levonantradol is qualitatively similar to that of cannabinoids but differs from that previously reported for narcotic analgesics. Moreover naltrexone (2 mg/kg intraperitoneally) does not reverse the effects of levonantradol on striatal or hippocampal TRACh. This pattern of activity on cholinergic dynamics elicited by levonantradol is consistent with a cannabinoid-like rather than an opioid-like mode of action.

Acetylcholine↗
PubMedDate not supplied

Grooming, alliances and reciprocal altruism in vervet monkeys.

Reciprocal altruism refers to the exchange of beneficial acts between individuals, in which the benefits to the recipient exceed the cost to the altruist. Theory predicts that cooperation among unrelated animals can occur whenever individuals encounter each other regularly and are capable of adjusting their cooperative behaviour according to experience. Although the potential for reciprocal altruism exists in many animal societies, most interactions occur between closely related individuals, and examples of reciprocity among non-kin are rare. The field experiments on vervet monkeys which we present here demonstrate that grooming between unrelated individuals increases the probability that they will subsequently attend to each others' solicitations for aid. Vervets appear to be more willing to aid unrelated individuals if those individuals have behaved affinitively toward them in the recent past. In contrast, recent grooming between close genetic relatives appears to have no effect on their willingness to respond to each other's solicitations for aid.

Altruism↗