Papers by C. Van Hartesveldt
The Hippocampus and Regulation of the Hypothalamic-Hypophyseal-Adrenal Cortical Axis
The Hippocampus, 1975
It has been established since 1950 that the hormones of the adrenal cortex are regulated by the c... more It has been established since 1950 that the hormones of the adrenal cortex are regulated by the central nervous system. The adrenal cortex is stimulated by adrenocorticotropic hormone (ACTH) carried through the circulatory system from the adenohypophysis, which is activated by corticotropin releasing factor (CRF) brought via the hypophyseal portal vessels from the median eminence of the hypothalamus. Many structures of the limbic system project to the hypothalamus and are therefore potential candidates for modulating adrenocortical hormone secretion. The hippocampus has been implicated in such a role since the late 1950s. The results of much of the research in this area have led many authors to conclude that the hippocampus inhibits hypothalamic mechanisms controlling the secretion of adrenal corticosteroid hormones. However, a close examination of the existing data reveals that this generalization is probably misleading oversimplification since (1) there is more than one functional system which has access to the final common path of adrenocortical steroid hormone secretion and (2) different methods of hippocampal disruption give results which lead to different conclusions about its function. In this chapter, the data relating to the role of the hippocampus in the regulation of this hormone system will be critically analyzed using these two points as an organizational framework.
Size of reinforcement and operant responding in hippocampectomized rats
Behavioral biology, 1973
ABSTRACT
Behavioral biology, 1977
In the present study, we have described a diurnal fluctuation in the open-field activity of rats.... more In the present study, we have described a diurnal fluctuation in the open-field activity of rats. Hippocampal lesions greatly magnify this diurnal fluctuation, primarily by increasing the activity observed in the morning prior to the onset of light. To test whether this diurnal fluctuation is related to the cyclic release of adrenal hormones, the subjects were adrenalectomized. Adrenalectomy did not abolish the diurnal pattern of locomotor activity, but it reduced both the morning and evening activities of rats with hippocampal lesions.
Rotation and postural deviation elicited by microinjections of dopamine into medial and lateral regions of dorsal striatum
Pharmacology, biochemistry, and behavior, 1984
Unilateral microinjections of DA (25 micrograms/0.25 microliter) into several medial to lateral r... more Unilateral microinjections of DA (25 micrograms/0.25 microliter) into several medial to lateral regions of the dorsal striatum of female rats produced both contralateral postural deviation and rotation. However, injections of DA into the medial striatum were more effective in producing rotation than postural deviation, whereas the opposite was the case for lateral striatal injections.
Synapse, 1993
The present study examined the effects of the dopamine D, receptor subtypes agonist SK&F 38393 on... more The present study examined the effects of the dopamine D, receptor subtypes agonist SK&F 38393 on locomotor activities after bilateral microinjection (0.00, 0.01, 0.1, 1.0,lO.O Fg) into the nucleus accumbens (Acb). The dose of 0.1 Fg elicited the highest response rate across measures of locomotion, rearing and stereotypy behavior. On the other hand, the largest dose of 10.0 pg was associated with significant increase in center time behaviors. The data were supportive of the hypothesis that dose-related locomotor activities elicited by microinjections of SK&F 38393 into the Acb are independently mediated by D, receptors.
Sulpiride antagonizes the biphasic locomotor effects of quinpirole in weanling rats
Psychopharmacology, 1995
Low doses of dopamine (DA) agonists such as the D2 receptor subfamily agonist quinpirole are thou... more Low doses of dopamine (DA) agonists such as the D2 receptor subfamily agonist quinpirole are thought to stimulate DA autoreceptors selectively, thereby inhibiting locomotor activity. High doses of quinpirole initially suppress and later activate locomotion during a single test-session; the activation is presumably due to stimulation of postsynaptic receptors. The aim of this study was to investigate whether pretreatment with a selective DA D2 receptor antagonist, sulpiride, could block the putative autoreceptor-mediated inhibition at a lower dose than was required to block the postsynaptically mediated activation. Male and female 30-day-old rats were injected SC with one of eight doses of sulpiride (0.313-40 mg/kg) or the vehicle. Sixty minutes later, rats were injected SC with 0.2 mg/kg quinpirole or the vehicle. Five minutes after the second injection, rats were placed in automated activity monitors which recorded locomotor behavior for 60 min at 5-min intervals. Quinpirole at this dose first suppressed and later increased locomotor activity. Sulpiride pretreatment dose-dependently reversed both the early inhibition and later activation of quinpirole-induced locomotion. However, sulpiride did not block the quinpirole-induced early suppression at a lower dose than was required to block the later activation. Thus, there was no evidence that the locomotor suppression elicited by quinpirole is mediated by a more sensitive subset of DA receptors.
Effects of intrastriatal and intracortical scopolamine on behavior in rats
Pharmacology Biochemistry and Behavior, 1984
The anticholinergic drug scopolamine (20 micrograms, 30 micrograms, 40 micrograms) or its vehicle... more The anticholinergic drug scopolamine (20 micrograms, 30 micrograms, 40 micrograms) or its vehicle was injected unilaterally into the dorsal anterior striatum or overlying rostral neocortex in rats in order to examine the role of each region in contralateral postural deviation and stereotyped rearing. Scopolamine-induced contralateral deviation was observed in all subjects with striatal injections (p less than 0.01), and was of the same magnitude at all dose levels. Intracortical scopolamine did not induce contralateral deviation. However, stereotyped rearing was elicited from both the striatum and neocortex (p less than 0.01) at the two highest dose levels of scopolamine. Thus the mechanisms for contralateral deviation and stereotyped rearing differ both with respect to brain region and drug sensitivity.
Pharmacology Biochemistry and Behavior, 1994
The effects of the dopamine D2/D3 receptor agonist quinpirole (LY171555) on locomotor activity we... more The effects of the dopamine D2/D3 receptor agonist quinpirole (LY171555) on locomotor activity were tested on rats of 10, 15, 20, 30, and 60 days of age. In two separate experiments, doses of 0 (vehicle), 0.02, 0.2, or 2.0 mg/kg qulnpirole were injected SC into rats at each age, and their effects measured either for 2 h at 15-rain intervals, or 30 rain at 5-rain intervals. At 10, 15, and 20 days of age, quinpirole significantly increased distance travelled in a dose-dependent manner. At 30 and 60 days of age, qulnpirole significantly decreased distance travelled early in the session and increased it later. These results suggest that a dopamine autoreceptor begins to function between 20 and 30 days of age. Concomitant with the appearance of quinpirole-indueed locomotor suppression early in the session, the amount of quinpirole-induced activation late in the session declined.
Differential effects of intrastriatal estradiol on the dorsal immobility response in male rats
Pharmacology Biochemistry and Behavior, 1992
Intracerebral haloperidol potentiates the dorsal immobility response in the rat
Pharmacology Biochemistry and Behavior, 1993
Pharmacology Biochemistry and Behavior, 1993
1993.-The effects of the dopamine DI antagonists R-(+)-7-chloro-8-hydroxy-3-methyl-lphenyl-2,3,4,... more 1993.-The effects of the dopamine DI antagonists R-(+)-7-chloro-8-hydroxy-3-methyl-lphenyl-2,3,4,5-tetrahydro-l-H-3benzazapine (SCH23390) and (+)-7-bromo-8-hydroxy-3-methyl-1-phenyl-2,3,4,5-tetrahydro-1-H-3-benzazapine (SK&F83566) were tested for 2 h on linear locomotor, rearing, stereotypy, and margin times in an open field. Each of the antagonists attenuated the duration of linear locomotion, rearing, and stereotypy times in a dose-and time-dependent manner. The effectiveness of the antagonists was relatively brief and SCH23390 was more effective than SK&F83566 on each behavior. The two antagonists had differential effects on margin time.
Temporal and Environmental Effects on Quinpirole-Induced Biphasic Locomotion in Rats
Pharmacology Biochemistry and Behavior, 1997
The dopamine D2/D3 agonist quinpirole induces suppression of locomotor activity at low doses, and... more The dopamine D2/D3 agonist quinpirole induces suppression of locomotor activity at low doses, and suppression followed by activation at high doses when given to rats of 30 days of age and older that are immediately placed in activity monitors. The duration of suppression is longer and the level of activation is lower at 60 than at 30 days of age, suggesting that the mechanism responsible for the suppression may play a role in the lesser activation in the older rats. However, habituation limits the ability to measure the duration of locomotor suppression. Therefore, 0, 0.2, or 0.2 mg/kg quinpirole was injected S.C. either 30, 60, or 120 min before placing male or female rats of 30 or 60 days of age in activity monitors for 30 min. At both ages, both doses of quinpirole suppressed activity when the animal was placed in the monitor 30 or 60 min after injection; at 60 days the drug also suppressed activity at 120 min after injection. Previously, 0.2 mg/kg quinpirole elicited locomotor activity 60 min after injection in rats placed immediately in activity monitors at both ages. Thus, not only time after injection but novelty of the environment are critical factors in the expression of locomotor suppression or activation in response to quinpirole.
Pharmacology Biochemistry and Behavior, 1984
In order to test whether estrogen acts directly in the dorsal striatum to affect dopamine-mediate... more In order to test whether estrogen acts directly in the dorsal striatum to affect dopamine-mediated behavior, ovariectomized female Long-Evans rats were given a unilateral striatal application of estradiol, injected systemically with apomorphine (APO), and tested for lateralization of stereotypic behaviors. In the first experiment, estradiol, cholesterol, or an empty cannula was inserted and the rat given 0.7 mg/kg APO 1--4 hours later. Rats directed their stereotypic behaviors to the side ipsilateral to the insert of estradiol with dorsal striatal inserts, but not with inserts in ventral striatum or neocortex. Neither cholesterol nor the empty cannula inserts were effective in producing lateralization of the stereotypic behaviors. In the second experiment, intrastriatal inserts of 17 rt-estradiol were ineffective in producing a lateralization of APO-induced stereotyped behavior. In the third experiment, several doses of APO (0.07, 0.75 and 3.0 mg/kg) were tested. At the highest dose no lateralization of APO-induced stereotypic behavior was observed. These results strongly suggest that estradiol acts directly in the dorsal striatum to antagonize APO and thus produce a lateralization of stereotypic behaviors (postural deviation). Estrogen Membrane receptor Postural deviation Dopamine and estrogen
Effects of estrogen on the basal ganglia
Neuroscience & Biobehavioral Reviews, 1986
Effects of Differential Hippocampal Damage upon Rhythmic and Stress-Induced Corticosterone Secretion in the Rat
Neuroendocrinology, 1975
The effects of dorsal, ventral, and near-total hippocampal lesions upon both rhythmic and stress-... more The effects of dorsal, ventral, and near-total hippocampal lesions upon both rhythmic and stress-induced corticosterone secretion in adult male rats were examined. All hippocampally-damaged, cortically-damaged, and intact rats showed rhythmic corticosterone secretion as measured in 4 blood samples for each animal taken at 6-h intervals at least 1 week apart. There were no significant differences among the groups. In addition, there were no significant differences in the amount of stress-induced corticosterone across experimental groups.
Journal of the Experimental Analysis of Behavior, 1974
The lever pressing of four foodand water-deprived rats was reinforced on concurrent variable-inte... more The lever pressing of four foodand water-deprived rats was reinforced on concurrent variable-interval schedules. Food reinforced one response, and water reinforced the other. Response rates in baseline were higher in the food component than in the water component. After response patterns and body weights had stabilized, the animals were given access to either food only, water only, both food and water, or neither food nor water (baseline) before daily sessions. Giving food before a session decreased per cent time in the food component, decreased overall response rates for food, and increased overall response rates for water. Giving water before a session increased per cent time in the food component, increased overall response rates for food, and decreased overall response rates for water. Giving both food and water before a session resulted in a combination of prefeeding and prewatering effects. More food and more water were consumed when both were available than when only one was available before a session.
Transient midline raphe glial structure in the developing rat
The Journal of Comparative Neurology, 1986
A major glial structure is present during development within the midline raphe of the midbrain, h... more A major glial structure is present during development within the midline raphe of the midbrain, hindbrain, and cervical spinal cord of the rat. It is composed of great numbers of glial cell bodies lying immediately ventral to the cerebral ventricular system and the large radial processes extending from these cells toward the ventral surface of the brain roughly within the midsagittal plane. There is also a smaller group of glial cells on the dorsal surface of the aqueduct and the central canal whose processes extend to the dorsal surface of the brain. The entire structure exhibits an intensely positive immunoreactivity with the antibody to the S-100 protein, a nervous-system-specific protein found primarily in the cytoplasm of astrocytes. This immunoreactivity makes possible a clear visualization of the extent, magnitude, and continuity of this structure from at least embryonic day 15, the first age examined, until postnatal days 7-8, when it is no longer visible by this technique. This glial structure has several prominent morphological characteristics. During prenatal and early postnatal development the fibers forming the ventral aspect of the structure in the midbrain and hindbrain are formed into two parallel plates on either side of the midline with S-100-negative tissue between the plates. As development progresses, S-100-positive fibers are continually added so that the plates become thicker at the expense of the nonstaining intervening area. By postnatal day 4 only a single midline plate of fibers is visible, occupying the entire midline raphe. In the region of the pontine flexure the entire structure takes on a distinctly pleated configuration. This fact produces a curious "sine wave" appearance when the plane of section crosses these vertical pleats. At postnatal day 5 the structure begins to disappear, and it is no longer visible by 7-8 days postnatal. This glial structure does not stain with antisera to glial fibrillary acidic protein, a protein associated with fibrous astrocytes, or routine cell stains such as cresyl violet. With these techniques the raphe area appears essentially devoid of identifiable cellular elements.
Experimental Neurology, 1972
Estradiol suppresses then enhances intracaudate dopamine-induced contralateral deviation
European Journal of Pharmacology, 1982
European Journal of Pharmacology, 1999
This developmental study was an investigation of locomotion induced by the NMDA receptor antagoni... more This developmental study was an investigation of locomotion induced by the NMDA receptor antagonist, q MK-801 hydrogen wŽ .Ž. w x x maleate 5R,10Sq-5-methyl-10,11-dihydro-5H-dibenzo a,d cyclohepten-5,10-imine , at doses of 0, 3 or 10 mg injected bilaterally into the nucleus accumbens of rats at 11, 21, 31, or 61-66 days of age. During a 2-h test session, only a few 11-day-old pups responded to either dose of MK801; they displayed short bouts of obstinate progression. In contrast, 21-and 31-day-olds were not affected by 3 mg MK801 but exhibited robust activation after 10 mg MK801. The activation was greatest in 21-day-olds and also occurred after mid-striatal injections in 21-but not 31-day-old rats. Adult rats injected with MK801 were not robustly activated, but they maintained their initial level of activity throughout the test session, instead of habituating to the test monitor, as controls did. Ontological changes in MK801-induced activity are likely to reflect maturation of glutamate transmission in the nucleus accumbens.
Uploads
Papers by C. Van Hartesveldt