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R H Porter

Publications and source records attributed to R H Porter.

87 records · Page 5Linked to original sources
PubMed1975

The responses of one-day old Acomys cabirinus pups to naturally occurring chemical stimuli.

The role of olfactory stimuli in the mediation of the behavior of 26--36 hour old spiny mice (Acomys cabirinus) was assessed through a series of six experiments. The major results of these experiments are: 1. One day old spiny mice showed a preference for soiled bedding from their own home-cage as compared to clean bedding in a simultaneous two-choice preference test. 2. No significant preference was displayed for home-cage bedding vs. bedding from the cage of a conspecific litter and parents. 3. Soiled bedding from the home-cage was preferred over soiled bedding from the cage of a nulliparous adult female conspecific. 4. A reduced mean latency to leave an area of clean bedding was found in comparison to mean latencies to leave soiled bedding from the subjects' home-cage or from the cage of a conspecific litter. 5. No differential activity levels were displayed on home-cage vs. clean bedding. It was concluded that by the second day of life, Acomys pups have developed attachment to chemical stimuli produced by specific classes of conspecifics--and that the early appearance of such attachments is a function of the high degree of sensory and motor precocity of the Acomys pups at birth. The adaptive value of such rapidly developed attachments in precocial as contrasted to altricial species was discussed.

Age Factors↗
PubMedDate not supplied

Modulation of 5-HT(2A) receptor-mediated head-twitch behaviour in the rat by 5-HT(2C) receptor agonists.

The pharmacology of several commonly described 5-hydroxytryptamine (5-HT)(2C) receptor agonists was investigated in vivo and in vitro at rat 5-HT(2A), 5-HT(2B), and 5-HT(2C) receptors. The 5-HT(2C) receptor agonist, (S)-2-(6-chloro-5-fluoroindol-1-yl)-1-methylethylamine fumarate (Ro 60-0175), did not induce a significant head-twitch response when given alone, yet when administered to rats subsequent to an acute challenge with the selective 5-HT(2C) receptor antagonist, 6-chloro-5-methyl-1-[6-(2-methylpyridin-3-yloxy) pyridin-3-yl carbomyl] indoline (SB-242084), a robust head-twitch response was observed which was blocked by the selective 5-HT(2A) receptor antagonists R(+)-alpha-(2,3-dimethoxyphenyl)-1-[2-(4-fluorophenyl-ethyl)]-4-piperidine-methanol (MDL 100907) or ketanserin. The preferential 5-HT(2C) receptor agonists Ro 60-0175, 6-chloro-2-[1-piperazinyl]-pyrazine HCl (MK-212), 1-(3-chlorophenyl)piperazine hydrochloride (mCPP), 1-(3-trifluoromethylphenyl)piperazine hydrochloride (TFMPP), and (S)-3-[(2,3-dihydro-5-methoxy-1H-inden-4-yl)oxy]-pyrollidine HCl (ORG-37684), the 5-HT(2A/2C) receptor agonist 2,5-dimethoxy-4-iodoamphetamine (DOI), the 5-HT(2B) receptor agonist 1-[5-thienylmethoxy-1-1H-3-indoyl] propan-2-amine hydrochloride (BW-723C86), and nor-D-fenfluramine were administered to rats subsequent to an acute challenge of SB-242084. Under such conditions, each agonist, with the exception of BW-723C86, induced a dose-dependent increase in the incidence of head twitches. The pharmacology of the same agonists was determined at cloned rat 5-HT(2) receptors using a fluorometric imaging plate reader (FLIPR). Both the in vivo and in vitro data suggest that for some ligands, previous reports have overestimated their in vivo selectivity for the 5-HT(2C) receptor.

Animals↗
PubMedDate not supplied

Olfaction and human kin recognition.

Humans, like other mammals, are capable of discriminating between kin and non-kin by olfactory cues alone. Shortly after birth, breastfed infants become familiar with, and respond preferentially to, their mother's unique odor signature. Mothers likewise recognize the characteristic scent of their newborn infant. Close biological relatives share somewhat similar odor signatures (presumably resulting from genetically mediated similarities in bodily biochemistry and metabolism) that could facilitate kin recognition.

Animals↗
PubMedDate not supplied

Effects of early odor exposure in domestic chicks.

The effects of odor exposure during the last 2 days of incubation and immediately after hatching on subsequent responses by chicks to that same scent were assessed. When tested with an orange-treated and an unscented container, chicks that had been previously exposed to orange odor more rapidly approached both containers than did control chicks and spent more time near them. In both conditions, chicks spent significantly more time near the unscented container than the one treated with orange. In a second experiment, chicks previously exposed to orange odor and control chicks did not differ in their rates of locomotor activity or latency to approach stimulus containers when orange odor was not present. Chicks become familiar with specific odors as a function of early exposure. Differences between the behavior of exposed and naive chicks in the presence of orange odor may reflect neophobic responses by the controls.

Animals↗