1 |
Pimozide and Sham Feeding: Addition of the Postingestive Cues of Cholecystokinin or Glucose / Pimozide and Sham FeedingBondar, Jay 09 1900 (has links)
The present thesis examined the potential interaction between postingestive cues and the dopamine antagonist pimozide on the inhibition of sucrose sham intake. Coadministration of CCK and pimozide IP produced additive inhibitory effects on sham feeding of 4% or 17.1% sucrose. Manipulations of blood glucose levels by infusion of 10% dextrose or injection of 0.1U insulin SC did not interact with pimozide to alter the latter drug's inhibition of 34.2% sucrose sham feeding. Separate experiments verified that these manipulations significantly altered blood glucose levels compared to a control 0.9% saline infusion IV. Infusions of d-glucose into the lateral ventricle significantly enhanced the inhibitory effects of pimozide on 34.2% sucrose sham intake compared to infusions of!glucose or 2-deoxy-glucose. Infusions of d-glucose into the third ventricle, however, significantly attenuated the inhibitory effects of pimozide on 34.2% sucrose sham feeding compared to the control l-glucose infusions. These results collectively suggest that some postingestive cues, such as elevations in third ventricle glucose levels, are indeed capable of inhibiting the suppressive effects of pimozide on sucrose sham feeding. / Thesis / Master of Science (MSc)
|
2 |
Postabsorptive Glucose Decreases the Excitatory Effects of Taste on IngestionBedard, Michel 12 1900 (has links)
To test the hypothesis that postprandial rises of plasma
glucose attenuate the motivation derived from positive
tastes, I analyzed the effects of intraperitoneal (ip)
injections of glucose on sham feeding, a preparation in
which food intake is motivated primarily by taste
sensations. IP glucose suppressed sham feeding, with
maximal suppressions approximating 42%, but only when
glucose was administered contiguous with oropharyngeal
stimulation. The food intake inhibition produced by ip
glucose interacted with palatability; smaller doses of
glucose were required to suppress less concentrated sucrose
solutions. Closing the gastric cannula increased the
potency with which ip glucose inhibited eating suggesting
synergy of postabsorptive glucose with other postgastric
satiety signals. The inhibition of eating produced by ip
glucose did not result from malaise. Thus, postabsorptive
rises of plasma glucose decrease the ability of taste cues
to drive ingestion and suggest that this phenomenon may
contribute to spontaneous meal termination. / Thesis / Master of Science (MSc)
|
3 |
The effects of haloperidol infusions into the hypothalamus and nucleus accurnbens on sucrose sham feedingTurenne, Sylvie 09 1900 (has links)
<p> The present thesis examined the relative contribution of hypothalamic and nucleus accumbens dopaminergic activity to the control of sucrose sham feeding. Bilateral intracranial infusions of the dopamine antagonist, haloperidol at doses of 1.25, 2.5, 5 and 7.5 ug, into the hypothalamus and nucleus accumbens produced dose-dependent suppressions of sham feeding of a 15% sucrose solution. No differences in temporal pattern of intake were observed between hypothalamic and nucleus accumbens infusions under drug or vehicle conditions. Also, motor deficits were observed with the highest dose of haloperidol (7.5 ug) while the three lower doses inhibited sham feeding without obvious signs of motor impairment. These results suggest that mesolimbic as well as hypothalamic dopaminergic activity mediate the hedonic aspects of feeding. </p> / Thesis / Master of Science (MSc)
|
4 |
An Investigation of the Parameters of CCK-Induced SatietyForsyth, Peter Alexander 07 1900 (has links)
Two major aspects of CCK-induced satiety were examined in the
food deprived sham-feeding rat: the kinetics of the inhibition of
feeding produced by CCK and the interaction of CCK-induced satiety with
oropharyngeal stimulation. Four results were presented regarding the
kinetics of the CCK satiety effect. First, CCk administered coincident
with the initiation of sham feeding inhibits feeding in a dose-related
manner. Second, the increased efficacy of the higher dose of CCK
delivered at the same time as sham feeding results from an increase in
the size of maximum suppression and an increase in the time of
suppression effected via a decreased latency to suppression. Third, CCk
delivered 15 minutes before sham feeding begins has no effect on
feeding. Fourth, the administration of a long-lasting derivative of CCK
15 minutes prior to the initiation of sham feeding can suppress intake.
Two results were presented regarding the role of oropharyngeal
stimulation in CCK-induced satiety. First, it was shown that
oropharyngeal stimulation enhances the satiety action of CCK. Second,
the amount and pattern of feeding inhibition produced by CCK are
equivalent regardless of whether the peptide is administered coincident
with, or some time after, the initiation of sham feeding. The
implications of these results for the therapeutic use of this peptide
and its role in producing satiety are discussed. / Thesis / Master of Arts (MA)
|
Page generated in 0.0798 seconds