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At least 343 records · Page 19Linked to original sources
PubMed1985

Olfaction and behavioral modification in domestic chicks (Gallus domesticus).

Olfactory responsiveness in the female domestic chick was examined in a series of experiments. Individually-housed chicks preferred the familiar soiled substrate from their own home box to that soiled by a strange conspecific and to clean wood litter when placed in an otherwise novel Y maze. An artificial odorant present during the development of group-reared chicks subsequently proved attractive in an otherwise novel and potentially frightening situation. Chicks reared with one of two aromatic oils subsequently discriminated between them and preferred the familiar oil when both were present in the test box. The preferences are likely acquired because naive, one-day-old chicks reacted similarly to wood litter treated with either water or oil. Presence of a familiar rearing odor also reduced fear of a novel open field. In contrast to controls, chicks whose nostrils were blocked prior to rearing with an aromatic oil showed no subsequent preference for this odorant. The present results suggest that domestic chicks can regulate their behavior in response to olfactory cues though trigeminal chemoreception may also be involved.

Animals↗
PubMed1994

Hormonal and behavioral responses of male hamsters to females and female odors: roles of olfaction, the vomeronasal system, and sexual experience.

Removal of the vomeronasal organ eliminated androgen surges in male hamsters in response to female vaginal secretions in both sexually experienced and sexually naive males; lesions of the olfactory mucosa had no effect on such responses. Both lesions led to deficits in behavioral responses to vaginal secretions. In response to interactions with estrous females, in contrast, lesions of either system alone had no influence on androgen surges in males (either sexually experienced or naive). Lesions of both systems, however, eliminated androgen surges in sexually naive males but not sexually experienced males. These dual lesions eliminated male mating behavior, while lesions of either system alone had little influence on mating. There were no significant correlations in any experiment between level of behavioral responses and degree of change in androgen levels. Thus, we conclude that the vomeronasal system mediates androgen surges in response to female odors but is not necessary for such responses to females themselves. In sexually naive males the vomeronasal and olfactory systems together are necessary for androgen responses to females. Behavioral responses were influenced by lesions and by sexual experience. Lesions of both systems increased the latency to investigate vaginal secretions, and sexual experience decreased the latency and increased the duration of investigation. Lesions and experience also influenced male sexual performance.

Androgens↗
PubMed1994

Olfaction mediates the establishment of selective bonding in goats.

Nine pregnant goats of the Creole breed were rendered anosmic 3 weeks before parturition by irrigating their olfactory mucosa with zinc sulfate, and nine additional pregnant goats were left intact. At parturition, interactions between all females and their young were observed for 1 h. No differences were found in mother-young relationships between intact and anosmic mothers during this time, except that kids from anosmic females were slower to suck than controls. After 4 h of uninterrupted mother-young, mothers underwent three successive 5-min tests in a predetermined order to study selective bonding: with their own kid, an alien kid of similar coat color and pattern, and an alien kid of dissimilar coat color and pattern. Intact goats readily discriminated between kids, and rejected the two aliens while accepting their own. By contrast, anosmic mothers showed no signs of discrimination and accepted the three types of kids. It is concluded that during the first postpartum hours of contact, mother goats memorize individual olfactory characteristics of their kid that serve as a basis for selective suckling and exclusive bonding. Furthermore, at this early stage, visual characteristics of the young do not appear able to compensate for the loss of olfactory cues.

Animals↗
PubMed1994

Retronasal or internasal olfaction can mediate odor-guided behaviors in newborn mice.

Studies of olfactory deprivation have most frequently used unilateral naris occlusion to effect deprivation. Recent psychophysical evidence suggests that adult rodents with either acute or chronic naris occlusion show little decrement in olfactory ability. In this study the effect of naris occlusion coupled with ipsilateral or contralateral olfactory bulb deafferentation on odor-guided behaviors was tested in neonatal mice. Animals that received bilateral bulbectomy or control manipulation were also included. In Experiment 1, olfactory lesions were produced by bulb aspiration on the second day after birth (P2). Daily weight gain, a reliable measure of suckling success, was recorded until P21. In Experiment 2, olfactory lesions consisted of bulb transection on P2. Daily weights were recorded until subjects were P10. Animals with bilateral bulbectomy had the highest mortality rate and slowest growth rate. Both naris occlusion groups grew more slowly than controls but were not significantly different at P5 or P10. They diverged, thereafter, such that at P20 the group with naris occlusion ipsilateral to bulbectomy was similar to controls, while the contralateral group was similar to the bilateral bulbectomy group. In Experiment 2, the weights of the naris occlusion groups diverged by the day after surgery, with the contralateral group suffering the most arrested growth. Behavioral tests were combined from the two experiments for analysis. Subjects were tested at P5 for their ability to find the nipple, at P8 for their ability to find the nest, and at P10 for unwashed vs. washed nipple preferences. Only the contralateral group had a significantly depressed ability to find the nipple, while all lesions groups had a significant but similar decline in nest-finding ability.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗
PubMed1996

Appetitive sexual behavior in male rats: 1. The role of olfaction in level-changing behavior.

Level-changing behavior is a form of anticipatory behavior of a male rat, when tested in a bilevel testbox. The male explores the testcage prior to introduction of a female. The female is introduced after 5 min. The number of level changes displayed by the male in this period reflects appetitive aspects of sexual behavior and it was suggested that analysis of this level-changing behavior may function as assessment of sexual motivation. In this study the increase of anticipatory level changes over repeated weekly tests was dependent upon (sexual) olfactory stimulation. The number of anticipatory level changes was reliably reduced by administration of the opioid antagonist naloxone, suggesting that endogenous opioids facilitate this behavior. These results suggest that the increase of anticipatory level changes over repeated tests is a response to olfactory stimuli and reflects appetitive aspects of sexual behavior, which are stimulated by endogenous opioids. These results are in accordance with the concept that analysis of anticipatory level-changing behavior can be used to assess sexual motivation.

Animals↗
PubMed1984

Studies in canine olfaction, taste and feeding: a summing up and some comments on the academic-industrial relationship.

The authors discuss two principal points. First, what appear to be contradictory findings in the feeding studies in this monograph can be resolved by clarifying two terms: palatability and preference. Second, some of the work in the monograph resulted from an academic and industrial relationship. This relationship was judged mutually beneficial and productive. The primary benefits are discussed along with what are considered the key ingredients for a successful joint venture.

Animal Feed↗
PubMed1991

Olfaction in Drosophila: genetic and molecular analysis.

Drosophila melanogaster has a sophisticated yet relatively simple olfactory system, the function of which can be studied in vivo by either physiological or behavioral methods. Several genetic and molecular approaches have been applied to isolating and characterizing genes required for the function or development of the olfactory system. Recent analysis of some of these genes is beginning to provide insight into their functions.

Aldehydes↗
PubMed1993

Implications of the NO/cGMP system for olfaction.

The rapid and transient generation of pulses of either cAMP or IP3 is considered the primary reaction in olfactory signal transduction. There is some recent evidence suggesting that another second messenger system, involving cGMP, may also play an important role in olfactory signalling. High doses of odorant elicit a delayed and sustained elevation of cGMP levels due to the operation of the nitric oxide (NO) synthase/guanylyl cyclase system. The interplay of NO and cGMP is supposed to trigger molecular mechanisms, including adaptation processes, which enable the olfactory neuroepithelium to cope with strong stimuli. Furthermore, a characteristic pattern of staining for NO synthase in the olfactory bulb suggests that the NO/cGMP system may also participate in neuronal processing of the sensory input.

Animals↗
PubMed1982

The role of the medial olfactory pathways in olfaction: behavioral and electrophysiological data.

The role of the olfactory inputs transmitted by the medial olfactory pathways --i.e. anterior limb of the anterior commissure and medial forebrain bundle-was studied in rats submitted either to a bilateral lesion of the anterior commissure (bAC group) or to a bilateral transection of the lateral olfactory tract followed by an anterior commissure bilateral lesion (bCL group). In the bCL group, the characteristic emotional reactions usually observed in sham-operated rats to biologically meaningful odorants (odor of a predator or of conspecifics) were no longer observed; in this group, the modulation of mitral cell electrical responses according to the biological meaning of the stimuli disappeared and no habituation was noted when the stimulations were repeated: few responses appeared at random; lastly, all the stimuli tested, the odor of conspecifics excepted, did not exert an awaking influence on the sleeping rats (slow wave sleep). On the contrary, emotional reactions were always observed in the bAC group, a slight increase of reactivity to the odorants was even noted. In this group of animals, the anterior commissure bilateral lesion induced a large increase of the bulbar responses to all the odorants; the habituation of the electrical responses disappeared, a large percentage of responses being always noted even for the tenth series of stimulation; these results point out the great inhibitory influence that the anterior commissure exerts on the olfactory bulb activity. In these bAC rats almost usual awaking influences were noted, however, the odor of conspecifics became as efficient as fox odor to awake the animals. Results are discussed in relation to the functional role of the medial and lateral olfactory pathways, the integrity of both the pathways being necessary for an accurate olfactory process.

Animals↗
PubMed1993

Interbulbar reciprocal inhibition in frog olfaction.

Frogs were submitted in acute experiments to electrical stimulation of both ipsi- and contralateral homologous olfactory nerve bundles subserving the dorsal olfactory mucosae. Mitral layer responses on one side were recorded. When both stimulations were given at different onset times and equal intensity, the ipsilateral mitral layer response fell to a sharp minimum of 42% when the contralateral stimulation was given 25 ms before the ipsilateral one. When both stimuli were adjusted for maximal temporal inhibition and the intensity of the contralateral stimulation was varied, the amplitude of the ipsilateral response decreased as the intensity of the contralateral stimulation increased until intensity equalization was obtained. This interbulbar inhibition was suppressed either by sagittal transection through the interbulbar adhesion or local infusion of bicuculline in the ipsilateral olfactory bulb. It was unaffected by transection of habenular commissure. These findings suggest first, that the neuroreceptors located in the dorsal olfactory mucosae project to both olfactory bulbs, and second, that it exists at mitral layer level of the frog, a reciprocal inhibition which can subserve frog orientation towards proximal odour source.

Animals↗
PubMed1995

Scopolamine blocks olfaction-induced fast waves but not olfactory evoked potentials in the dentate gyrus.

The presentation of some odorous materials such as xylene or toluene under the snout of rats has been shown to elicit 15-30 Hz fast-wave bursts in both the olfactory bulb and dentate gyrus. Electrical stimulation of the olfactory bulb elicits an evoked potential (latency of first peak is 16-18 ms) in the dentate gyrus. The present study demonstrates that scopolamine or atropine blocks toluene-induced fast-wave bursts in the dentate region and to a lesser degree in the olfactory bulb while leaving dentate gyrus electrically evoked potentials intact. Further, rhythmical burst stimulation of the olfactory bulb at fast-wave frequencies will elicit fast-wave-like oscillations in the dentate gyrus. These fast-wave-like events, unlike evoked potentials to single-pulse stimulation, are abolished after muscarinic receptor antagonism with atropine. Mechanisms at the olfactory bulb and dentate gyrus that produce fast oscillations may involve muscarinic cholinergic synapses while the simple transmission of single, non-oscillatory olfactory signals to the dentate gyrus does not.

Animals↗