Disappearance of hoarding and disorganization of eating behavior after ventral mesencephalic tegmentum lesions in rats.

Abstract

The effects of ventral mesencephalic tegmentum (VMT) radio-frequency lesions on spontaneous and complex behaviors, such as food hoarding and alimentary patterns, were investigated. Activity measures indicated that VMT lesions increased horizontal activity in a circular corridor as well as in an open field whereas vertical activity (rearing) was decreased. After 12 hr of food deprivation, food hoarding and alimentary patterns were evaluated in a square open field to which rats had free access from their home cage. Control rats hoarded food and had organized feeding behavior, but experimental rats did not hoard. Moreover, increasing the open-field illumination did not reverse this deficit. Similarly, the VMT lesion induced disruption of the adaptative alimentary behavior in response to food deprivation. A strong correlation was observed between hoarding scores and the extent of locomotor hyperactivity. These results are discussed in terms of a possible implication of limbic-midbrain mechanisms in which the meso-cortico-limbic dopaminergic AlO neurons originating in the VMT might have a primary role.

Adolescent Toluene Inhalation in Rats Affects White Matter Maturation with the Potential for Recovery Following Abstinence

“…Toluene injected directly into the ventral tegmental area increases dopaminergic neuronal firing and dopamine release in the nucleus accumbens [8], with chronic exposure to toluene leading to persistent dopaminergic dysfunction [61]. While no one neural pathway appears linked to the control of rearing activity, the mesocorticolimbic system, including dopaminergic neurons, are necessary for normal locomotor and exploratory behaviour [9], [62], with limbic-striatal connections thought to play key roles in the initiation and maintenance of locomotor activity [63] and lesions of the ventral tegmental area being sufficient to decrease rearing activity [64]. In line with this, altered ventral striatal dopamine activity and medial frontal cortical serotonergic activity [65] has been observed in Wistar rats with low rearing activity in a novel open field, however rearing activity normalises once novelty is removed following repeated exposure [56].…”

Evidence for estrogen receptor in cell nuclei and axon terminals within the lateral habenula of the rat: Regulation during pregnancy

“…There is evidence that the habenula is involved in such physiologic activities as sleep (Huan et al, 1992), sensitization to drug treatments (Funk and Stewart, 1992), and nociception Melzack, 1986, 1993;Mahieux and Benabid, 1987;Ternzi et al, 1990;Fuchs and Cox, 1993;Nagao et al, 1993). It plays a role in the display of several general behavioral categories, such as motor activity and exploration (Lee and Huang, 1988;Thornton et al, 1990;Corodimas et al, 1992) and carrying and hoarding behaviors (Stinus et al, 1978;Kelly and Stinus, 1985). There is also strong evidence that the habenular complex, particularly the LHb, is critical in several hormonally dependent reproductive behaviors, namely, female sexual receptivity, the hormonal induction of maternal behavior, and postpartum estrus behavior.…”

Distribution of Catecholamines in the Ventral Mesencephalon of Human Brain, with Special Reference to Parkinson's Disease

“…The ventral mesencephalic tegmentum, an area which connects forebrain and midbrain structures, contains in the rat a group of dopamine (DA) cells, the so-called A10 system, which projects to subcortical and cortical regions (Lindvall et al, 1974;Berger et al, 1976;Hokfelt et al, 1976). Lesions of the ventral tegmental area (VTA) result in permanently disturbed behaviour, manifested by hyperactivity, hypoemotivity, hypoexploration, confusion and disorganisation of orderly sequencing (le Moal et al, 1976;Galey et al, 1977;Stinus et al, 1978). Furthermore, these disturbances are well correlated with a decrease in DA in the forebrain, particularly in the frontal cortex (Tassin et al, 1978).…”