7 research outputs found

    The Histaminergic Tuberomamillary Nucleus Is Involved in Appetite for Sex, Water and Amphetamine.

    No full text
    The histaminergic system is one component of the ascending arousal system which is involved in wakefulness, neuroendocrine control, cognition, psychiatric disorders and motivation. During the appetitive phase of motivated behaviors the arousal state rises to an optimal level, thus giving proper intensity to the behavior. Previous studies have demonstrated that the histaminergic neurons show an earlier activation during the appetitive phase of feeding, compared to other ascending arousal system nuclei, paralleled with a high increase in arousal state. Lesions restricted to the histaminergic neurons in rats reduced their motivation to get food even after 24 h of food deprivation, compared with intact or sham lesioned rats. Taken together, these findings indicate that the histaminergic system is important for appetitive behavior related to feeding. However, its role in other goal-directed behaviors remains unexplored. In the present work, male rats rendered motivated to obtain water, sex, or amphetamine showed an increase in Fos-ir of histaminergic neurons in appetitive behaviors directed to get those reinforcers. However, during appetitive tests to obtain sex, or drug in amphetamine-conditioned rats, Fos expression increased in most other ascending arousal system nuclei, including the orexin neurons in the lateral hypothalamus, dorsal raphe, locus coeruleus and laterodorsal tegmental neurons, but not in the ventral tegmental area, which showed no Fos-ir increase in any of the 3 conditions. Importantly, all these appetitive behaviors were drastically reduced after histaminergic cell-specific lesion, suggesting a critical contribution of histamine on the intensity component of several appetitive behaviors

    Fos-ir pattern of AAS nuclei elicited by appetitive behavior.

    No full text
    <p>Left column in white (sex): Fos-ir after 30 min of exposure to receptive (proestrus n = 5) or to non-receptive (diestrus n = 5) females. Middle panel in light gray (drink): 48 hours of water deprivation followed by 30 minutes of enticing (Deprived enticed n = 14) or not (Deprived n = 6). Right column in dark gray (drug): 30 minutes of exposure to the place preference apparatus where the animals were conditioned to amphetamine (Amph. Conditioned), versus non-conditioned animals (Amph. non-Conditioned) and rats non-conditioned injected with saline, (saline). # p< 0.05 respect to the naïve circadian controls; * p< 0.05 between conditions. Kruskall Wallis one way ANOVA followed by all pairwise multiple comparisons (Dunn's Method).</p

    Quantification of the OrxB-SAP ribotoxin lesion of the TMN and adjacent structures.

    No full text
    <p>Photomicrographs of sections stained for ADA-ir (<b>a, b</b>) and Nissl substance (<b>c, d</b>). <b>(a)</b> and <b>(c)</b> show an intact TMN, (<b>b</b>) and (<b>d</b>) represent a large TMN lesion (77%) that involved the ventral (arrowhead) and the dorsal TMN (arrow). <b>(e)</b>, the quantification of Orx-ir neurons in the LHA or TH-ir neurons in the ventral tegmental area (VTA), demonstrated that these adjacent regions that express Orx receptors were spared by the Orx-SAP injections. No statistical differences were detected (Mann Whitney test, p = 0.216 and 0.811 respectively). Scale bars = 200 μm. <b>V3m</b> mammillary recess of the third ventricule.</p

    Photomicrograph of TMN neurons after re-exposure to the amphetamine place preferences apparatus.

    No full text
    <p><b>(a)</b> Double immunohistochemistry for Fos/ADA in the tuberomamillary nucleus of a naïve (circadian control) rat. <b>(b)</b> Double immunohistochemistry for Fos/ADA in the TMN of an amphetamine conditioned rat, after 30 minutes of re-exposure to the amphetamine place preference apparatus. Arrows in <b>(a)</b> depict ADA-ir neurons; arrows in <b>(b)</b> depict double-ir neurons Fos/ADA. Scale bar, 200 μm.</p

    Effect of TMN lesion on appetitive behavior.

    No full text
    <p>(<b>a)</b> TMN lesion decreased the sniffing time of male rats challenged by a receptive female (proestrus) to a level similar to that elicited by non-receptive females (diestrus).(<b>b)</b> dorsal TMN and dorsal plus ventral TMN lesions were sufficient to reduce sexual appetitive behavior respect to the intact group. (<b>c)</b> TMN lesion decreased licking time of water deprived animals enticed by an empty drinking bottle. (<b>d)</b> The lesion had to involve both TMN divisions to be effective on drinking behavior. (<b>e)</b> TMN lesion decreased the time spent in the amphetamine-paired box in conditioned rats. (<b>f),</b> rats with a dorsal TMN lesion showed the largest drop in appetitive behavior directed to obtain amphetamine. ANOVA of Ranks (Kruskall Wallis) followed by a post-hoc of multiple comparison, Dunn's method. * indicates p<0.05 respect to intact rats, # p<0.05 respect to the two other conditions. n/d, not detected.</p
    corecore