scholarly journals Carbohydrate and torpor duration in hibernating golden-mantled ground squirrels (Citellus lateralis)

1982 ◽  
Vol 147 (1) ◽  
pp. 129-135 ◽  
Author(s):  
Mark L. Zimmerman
Keyword(s):  
Ground Squirrels ◽  
Citellus Lateralis

Changes in CNS responsiveness during hibernation

1976 ◽  
Vol 231 (3) ◽  
pp. 810-816 ◽  
Author(s):  
AL Beckman ◽  
TL Stanton
Keyword(s):  
Reticular Formation ◽  
Ground Squirrels ◽  
Progressive Change ◽  
Midbrain Reticular Formation ◽  
Citellus Lateralis ◽  
Early Portion ◽  
Stimulation Of

The ability of the midbrain reticular formation (MRF) to produce thermogenic responses and to trigger arousal from hibernation was tested during successive quarters of individual hibernation bouts. Golden-mantled ground squirrels (Citellus lateralis) were implanted with bilateral cannula guides into the MRF. Single, bilateral, 1-mul injections of acetylcholine (ACh) at concentrations of 50, 100, or 200 mug/mul were delivered in each quarter of the same bout or in selected quarters of different bouts. The results show that the magnitude of thermogenic responses evoked by ACh stimulation of the MRF was depressed during the early portion of the bout and increased as time in the bout elapsed. Furthermore, the magnitude of responses evoked during hibernation was depressed in comparison to those evoked during euthermia, indicating the influence of inhibition on the responsiveness of the CNS during hibernation. We suggest that during hibernation, a progressive change in responsiveness of the CNS, perhpas focused in the MRF, controls the duration of each hibernation bout.

scholarly journals Control of plague vectors on diurnal rodents in the Sierra Nevada of California by use of insecticide bait-boxes

1960 ◽  
Vol 58 (3) ◽  
pp. 347-355 ◽  
Author(s):  
Allan M. Barnes ◽  
Leo Kartman
Keyword(s):  
Sierra Nevada ◽  
Host Species ◽  
Ground Squirrel ◽  
Ground Squirrels ◽  
Flea Species ◽  
Home Ranges ◽  
Sierra Nevada Mountains ◽  
Citellus Lateralis ◽  
Residual Control

Trials were conducted in the Sierra Nevada Mountains of California to test the effectiveness of 10% DDT dust in insecticide bait-box stations against the fleas of native diurnal rodents. The principle host species involved were the chipmunks Eutamias amoenus and E. speciosus, and the golden-mantled ground squirrel, Citellus lateralis. The important flea species were Monopsyllus eumolpi and M. ciliatus on chipmunks, and Diamanus montanus and Oropsylla idahoensis on ground squirrels. When baited daily for 12 days and furnished with 50 g. of 10% DDT dust, the bait-box stations reduced fleas strikingly within 24 hr., but very little residual control was obtained. A second application in which boxes were baited only twice weekly but for 28 days, also resulted in rapid knockdown and a residual control still effective 42 days after removal of the bait-boxes. The effect of the DDT was apparent at a distance of 400 ft. from the nearest bait-box due to the relatively extensive home ranges of the hosts. Although, in these trials, bait-box stations were spaced 100 ft. apart, 200 ft. spacing probably would be as effective with these hosts.

Characterization of midbrain component of the trigger for arousal from hibernation

1976 ◽  
Vol 230 (2) ◽  
pp. 368-375 ◽  
Author(s):  
AL Beckman ◽  
E Satinoff ◽  
TL Stanton
Keyword(s):  
Body Temperature ◽  
Ambient Temperature ◽  
Reticular Formation ◽  
Functional Organization ◽  
Ground Squirrels ◽  
Anterior Hypothalamus ◽  
Midbrain Reticular Formation ◽  
Citellus Lateralis ◽  
Arousal Mechanism

The ability of the midbrain reticular formation (MRF) to trigger arousal from hibernation and to change body temperature (Tb) during euthermia was tested in golden-mantled ground squirrels (Citellus lateralis). During hibernation (ambient temperature 5-6 degrees C) microinjections of cholinomimetic compounds (acetylcholine and carbachol) triggered full arousal or produced transient increases in Tb in 15 out of 19 tests; MRF microinjections of norepinephrine (NE) and 5-hydroxytryptamine (5-HT), at the same concentrations that produced full arousal when microinjected into the preoptic/anterior hypothalamus (PO/AH) area in previous experiments, has no effect on Tb in 13 out of 16 tests. In experiments on euthermic ground squirrels tested at an ambient temperature of 25 degrees C, MRF microinjections of acetylcholine raised Tb, whereas the monoamines had no significant effects. These results show that cholinoceptive neurons in the MRF can trigger arousal from hibernation and increase Tb during euthermia. The failure of NE and 5-HT to produce any significant effects at the same doses that were reported to be effective in the PO/AH indicates that the functional organization of the MRF portion of the arousal mechanism is different from that reported for the PO/AH.

Effect of hypoxia on glycolysis in perfused hearts from rats and ground squirrels (Citellus lateralis)

1970 ◽  
Vol 35 (2) ◽  
pp. 403-414 ◽  
Author(s):  
Roy F Burlington ◽  
bertwell K Whitten ◽  
Carol M Sidel ◽  
Mary A Posiviata ◽  
Irving A Salkovitz
Keyword(s):  
Ground Squirrels ◽  
Citellus Lateralis ◽  
Perfused Hearts

Indirect body fat manipulation and its effect on hibernation cycles in Citellus lateralis

1979 ◽  
Vol 57 (5) ◽  
pp. 976-978 ◽  
Author(s):  
John A. Phillips
Keyword(s):  
Food Availability ◽  
Body Fat ◽  
Growth Rates ◽  
Fat Content ◽  
Ground Squirrels ◽  
Fat Reserves ◽  
Citellus Lateralis ◽  
Body Fat Content ◽  
External Conditions

Observations of 92 laboratory born and raised golden-mantled ground squirrels (Citellus lateralis) revealed different growth rates and hibernation cycles between individuals with normal and maloccluded incisors. Weaned maloccluded infants fed at depressed rates and did not accumulate sufficient fat reserves for torpor to occur during their initial overwintering period. These same squirrels, after having had their incisors periodically cut during the following spring, fed at higher rates which led to both an increased peak autumn body fat content and a normalization of hibernation patterns during the second winter. The results suggest that even though the external conditions (photoperiod, temperature, food availability) may be consistent with those required for hibernation, the internal (endogenous) cycling cannot be initiated until sufficient fat levels have been attained.

Inhibition of the CNA trigger process for arousal from hibernation

1976 ◽  
Vol 230 (4) ◽  
pp. 1018-1025 ◽  
Author(s):  
AL Beckman ◽  
TL Stanton ◽  
E Satinoff
Keyword(s):  
Mean Value ◽  
Ground Squirrels ◽  
Type I ◽  
Type Ii ◽  
Small Magnitude ◽  
Citellus Lateralis ◽  
Ceiling Temperature ◽  
Rate Of Increase ◽  
Formation Type ◽  
Duplicate Portion

Ground squirrels (Citellus lateralis) produced three distinct types of thermogenic response during hibernation. These responses were evoked spontaneously as well as after stimulation produced by brief handling, or after microinjection of acetylcholine into the midbrain reticular formation. Type I responses were characterized by small magnitude and a slow (mean rate, 0.03 degrees C/min), variable rising phase. Type II responses were characterized by a smooth, rapid rising phase with a mean rate of increase of 0.11 degrees C/min and by an abrupt reversal of the rising phase within a restricted ceiling temperature band with a mean value of 9.4 degrees C. The third type of response, full arousal, was characterized by a return of body temperature to euthermic (nonhibernating) levels and by an early rising phase that was indistinguishable from the rising phase of type II responses. This indicates that the rising phase of type II responses and the duplicate portion of full arousals are produced by a common neuronal mechanism that functions as the trigger for arousal from hibernation, and that this mechanism can be spontaneously inhibited when increasing internal temperature reaches a hibernation ceiling level.

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