scholarly journals Enhancement of Latent Inhibition by Chronic Mild Stress in Rats Submitted to Emotional Response Conditioning

2003 ◽  
Vol 10 (4) ◽  
pp. 327-333 ◽  
Author(s):  
Liana Lins Melo ◽  
Elenice A. de Moraes Ferrari ◽  
Nancy Airoldi Teixeira ◽  
Guy Sandner
Keyword(s):  
Central Nervous System ◽  
Latent Inhibition ◽  
Emotional Response ◽  
Conditioned Emotional Response ◽  
Chronic Mild Stress ◽  
Control Group ◽  
Mild Stress ◽  
Response Training ◽  
Stressed Group ◽  
The Central Nervous System

This work evaluated the influence of chronic mild stress on latent inhibition (LI) in rats, using a conditioned emotional response (CER) procedure. Rats were assigned to four groups: a non pre-exposed control group (NPC), a non pre-exposed stressed group (NPS), a preexposed control group (PC), and a pre-exposed stressed group (PS). Stressed animals were submitted to a chronic mild stress (CMS) regimen for three weeks. The off-baseline conditioned emotional response procedure had four phases: licking response training, tone- shock conditioning, retraining, and testing. Conditioning consisted of 2 tone (30 s) and shock (0.5 s) associations. Tone-shock conditioning evidenced by NPS and NPC groups suggests that stress did not interfere with the expression of a conditioned emotional response. Pre-exposure was carried out using 6 tones (30 s) during 2 sessions before conditioning. Prior exposure to the tone resulted in a decrease in learning that was greater in stressed animals. The results indicate an increase in latent inhibition induced by chronic mild stress. Such LI potentiation after CMS may be related to dopamine (DA) neurotransmission reduction in the central nervous system.

An Investigation of the Effects of Curcumin on the Changes in the Central Nervous System of Rats Exposed to Aroclor 1254 in the Prenatal Period

2018 ◽  
Vol 17 (2) ◽  
pp. 132-143 ◽  
Author(s):  
Mehmet Eray Alcigir ◽  
Halef Okan Dogan ◽  
Begum Yurdakok Dikmen ◽  
Kubra Dogan ◽  
Sevil Atalay Vural ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Neuron Specific Enolase ◽  
Control Group ◽  
Albino Rats ◽  
Prenatal Period ◽  
Aroclor 1254 ◽  
Rat Pups ◽  
Tunel Reaction ◽  
The Central Nervous System

Background & Objective: Aroclor 1254 is a widespread toxic compound of Polychlorinated Biphenyls (PCBs), which can create significant nervous problems. No remedies have been found to date. The aim of this study was to reveal the damage that occurs in the central nervous system of rat pups exposed to Aroclor 1254 in the prenatal period and to show the inhibiting effect of curcumin, which is a strong anti-oxidant and neuroprotective substance. Method: The study established 3 groups of adult female and male Wistar albino rats. The rats were mated within these groups and the offspring rats were evaluated within the group given Aroclor 1254 only (n=10) and the group was given both Aroclor 1254 and curcumin (n=10) and the control group (n=10). The groups were compared in respect of pathomorphological damage. The immunohistochemical evaluation was made of 8-hydroxdeoxyguanosine (8-OHdG), 4-hydroxynoneal (4HNE), myelin basic protein (MBP) expressions and TUNEL reaction. The biochemical evaluation was made of the changes in the TAS-TOS and Neuron Specific Enolase (NSE) levels. Damage was seen to have been reduced with curcumin in the 8OHdG and TUNEL reactions, especially in the forebrain and the midbrain, although the dosage applied did not significantly change TAS and TOS levels. Consequently, it was understood that Aroclor 1254 caused damage in the central nervous system of the pup in the prenatal period, and curcumin reduced these negative effects, particularly in the forebrain and the midbrain. Conclusion: It was concluded that curcumin could be a potential neuroprotective agent and would be more effective at higher doses.

scholarly journals Effects of Electroacupuncture on Pain Threshold of Laboring Rats and the Expression of Norepinephrine Transporter andα2 Adrenergic Receptor in the Central Nervous System

2016 ◽  
Vol 2016 ◽  
pp. 1-8
Author(s):  
Qianli Tang ◽  
Qiuyan Jiang ◽  
Suren R. Sooranna ◽  
Shike Lin ◽  
Yuanyuan Feng ◽  
...  
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Adrenergic Receptor ◽  
Pain Threshold ◽  
Norepinephrine Transporter ◽  
Control Group ◽  
Tail Flick ◽  
Pregnant Rats ◽  
Tail Flick Test ◽  
The Central Nervous System

To observe the effects of electroacupuncture on pain threshold of laboring rats and the expression of norepinephrine transporter andα2 adrenergic receptor in the central nervous system to determine the mechanism of the analgesic effect of labor. 120 pregnant rats were divided into 6 groups: a control group, 4 electroacupuncture groups, and a meperidine group. After interventions, the warm water tail-flick test was used to observe pain threshold. NE levels in serum, NET, andα2AR mRNA and protein expression levels in the central nervous system were measured. No difference in pain threshold was observed between the 6 groups before intervention. After intervention, increased pain thresholds were observed in all groups except the control group with a higher threshold seen in the electroacupuncture groups. Serum NE levels decreased in the electroacupuncture and MP groups. Increases in NET andα2AR expression in the cerebral cortex and decreases in enlarged segments of the spinal cord were seen. Acupuncture increases uptake of NE via cerebral NET and decreases its uptake by spinal NET. The levels ofα2AR are also increased and decreased, respectively, in both tissues. This results in a decrease in systemic NE levels and may be the mechanism for its analgesic effects.

Effect of a central CRF antagonist on cardiovascular and thermoregulatory responses induced by stress or IL-1 beta

1993 ◽  
Vol 265 (4) ◽  
pp. R834-R839 ◽  
Author(s):  
T. Nakamori ◽  
A. Morimoto ◽  
N. Murakami
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Interleukin 1 ◽  
Corticotropin Releasing Factor ◽  
Mild Stress ◽  
Induced Responses ◽  
Interleukin 1 Beta ◽  
The Central Nervous System ◽  
Beta 2

We investigated the role of central corticotropin-releasing factor (CRF) in the development of cardiovascular and thermal responses induced by stress or by interleukin-1 beta (IL-1 beta) in free-moving rats. Intracerebroventricular (icv) injection of alpha-helical CRF9-41 (10 micrograms), a CRF receptor antagonist, significantly attenuated hypertension, tachycardia, and a rise in body temperature induced by cage-switch stress, a mild stress. However, icv injection of alpha-helical CRF9-41 (10 micrograms) had no effect on hypertension, tachycardia, or fever induced by intraperitoneal (ip) injection of IL-1 beta (2 micrograms/kg) or icv prostaglandin E2 (PGE2, 100 ng). In contrast, icv injection of alpha-helical CRF9-41 (10 micrograms) significantly attenuated hypertension, tachycardia, or fever induced by icv injection of IL-1 beta (20 ng). The present results suggest that central CRF has an important role in the development of the cage-switch stress-induced responses, but it does not seem to contribute to the hypertension, tachycardia, and fever induced by ip IL-1 beta or by central PGE2. However, it is possible that when IL-1 beta directly acts on the central nervous system, some of its actions are mediated by central CRF.

scholarly journals Analysis of electrogenesis’ changes in mental retardation persons by using computer electroencephalography

2021 ◽  
Vol 11 (11) ◽  
pp. 249-265
Author(s):  
B. Lobasyuk ◽  
L. Bartsevich ◽  
A. Zamkovaya
Keyword(s):  
Central Nervous System ◽  
Nervous System ◽  
Mental Retardation ◽  
Theta Rhythm ◽  
Cognitive Activity ◽  
Control Group ◽  
Bioelectrical Activity ◽  
The Central Nervous System ◽  
Beta Rhythms ◽  
The Brain

Justification. Mental retardation is a persistent decrease in human cognitive activity against the background of organic damage to the central nervous system. Neurophysiological diagnostics, in particular electroencephalography (EEG), most adequately reflects the morpho-functional state of the central nervous system, which is the basis of the mechanisms of mental activity, and the originality of the bioelectrical activity of the brain can be considered as the main indicator that determines a decrease in the level of intellectual development and, thereby, characterizes this state. This provision actualizes the search for highly informative indicators of the originality of the bioelectrical activity of the brain in children with intellectual disabilities. Purspose. With the use of periodometric analysis investigate EEG’s indicators and interhemispheric asymmetry of rhythms amplitudes in MR patients. Materials and methods. The EEG was recorded in a state of calm wakefulness with closed eyes with Neuron-Spectrum-2 electroencephalograph. Differences in indicators were tracked using the calculation of the coefficient of compliance (CC), EEG functional asymmetry coefficients in amplitude were determined, too. Results. It was revealed that in MR patients the amplitudes of the rhythms were greater than in healthy subjects. The greatest increase was determined in theta rhythm in the anterior temporal and posterior temporal leads in the left hemispheres. Duration indices in the delta, theta and alpha ranges of the EEG in mental retardation compared with the control group were increased, and the indices of the duration of beta rhythms - decreased. When analyzing FMPA in MR persons it turned out that in right-handers the negativeness of FMPA indices increased, and in left-handers there was an increase in the positivity of FMPA indices. Conclusions 1. With mental retardation, the amplitudes of the rhythms were greater than in healthy people. The greatest increase was determined in theta rhythm in the anterior temporal and posterior temporal leads in the left hemispheres. 2. The indices of duration in the delta, theta and alpha ranges of the EEG of MR subjects were increased, and the indices of the duration of beta rhythms – decreased. 3. When analyzing FMPA in MR persons, it turned out that in right-handers the negativeness of FMPA indices increased, and in left-handers there was an increase in the positivity of FMPA indices.

Participation of central alpha-receptors on hemodynamic response to E. coli endotoxin

1984 ◽  
Vol 247 (4) ◽  
pp. R655-R662
Author(s):  
S. Koyama
Keyword(s):  
Blood Pressure ◽  
Central Nervous System ◽  
Heart Rate ◽  
Time Course ◽  
Hypotensive Effect ◽  
Control Group ◽  
E Coli ◽  
Alpha Receptors ◽  
Anesthetized Dogs ◽  
The Central Nervous System

The time course of changes in mean blood pressure (MBP), heart rate (HR), and renal blood flow (RBF) in a control group of anesthetized dogs given only endotoxin (1 mg/kg iv) was compared with groups pretreated with alpha-antagonists either intravenously or intracisternally (ic). The decreases in MBP and RBF in the control group were abolished by intracisternal prazosin (0.1 mg/kg ic). MBP response to endotoxin after intravenous prazosin did not differ from that of the control group; however, the endotoxin-induced decrease in RBF after intravenous prazosin was significantly greater than that in the control group. HR responses to endotoxin were not altered by either intracisternal or intravenous prazosin. MBP and RBF responses to endotoxin after intravenous or intracisternal yohimbine (0.5 mg/kg iv or ic) did not differ from the control responses. However, significant differences occurred in the time course of changes in HR only when yohimbine was administered intracisternally. These observations suggest that the hypotensive effect and reduction of RBF due to endotoxin may be mediated by alpha 1-adrenoceptors at least in the central nervous system and that of HR response may be mediated alpha 2-adrenoceptors.

scholarly journals Dopamine in nucleus accumbens: salience modulation in latent inhibition and overshadowing

2011 ◽  
Vol 25 (12) ◽  
pp. 1649-1660 ◽  
Author(s):  
AJD Nelson ◽  
KE Thur ◽  
CA Marsden ◽  
HJ Cassaday
Keyword(s):  
Nucleus Accumbens ◽  
Conditioned Stimulus ◽  
Latent Inhibition ◽  
Relative Intensity ◽  
Emotional Response ◽  
Conditioned Emotional Response ◽  
Neural Substrates ◽  
6 Hydroxydopamine

Latent inhibition (LI) is demonstrated when non-reinforced pre-exposure to a to-be-conditioned stimulus retards later learning. Learning is similarly retarded in overshadowing, in this case using the relative intensity of competing cues to manipulate associability. Electrolytic/excitotoxic lesions to shell accumbens (NAc) and systemic amphetamine both reliably abolish LI. Here a conditioned emotional response procedure was used to demonstrate LI and overshadowing and to examine the role of dopamine (DA) within NAc. Experiment 1 showed that LI but not overshadowing was abolished by systemic amphetamine (1.0 mg/kg i.p.). In Experiment 2, 6-hydroxydopamine (6-OHDA) was used to lesion DA terminals within NAc: both shell- and core- (plus shell-)lesioned rats showed normal LI and overshadowing. Experiment 3 compared the effects of amphetamine microinjected at shell and core coordinates prior to conditioning: LI, but not overshadowing, was abolished by 10.0 but not 5.0 µg/side amphetamine injected in core but not shell NAc. These results suggest that the abolition of LI produced by NAc shell lesions is not readily reproduced by regionally restricted DA depletion within NAc; core rather than shell NAc mediates amphetamine-induced abolition of LI; overshadowing is modulated by different neural substrates.

Haloperidol-induced parkinsonism is attenuated by varenicline in mice

2018 ◽  
Vol 29 (4) ◽  
pp. 395-401 ◽  
Author(s):  
Amit K. Sharma ◽  
Sparsh Gupta ◽  
Ranjan K. Patel ◽  
Neeta Wardhan
Keyword(s):  
Central Nervous System ◽  
Neurodegenerative Disorder ◽  
Behavioral Assessment ◽  
Treated Group ◽  
Striatal Dopamine ◽  
Control Group ◽  
The Central Nervous System ◽  
Group 5 ◽  
Novel Strategy ◽  
Group 1

Abstract Background Parkinson’s disease (PD) is a neurodegenerative disorder of the central nervous system (CNS). However, there is no known drug to stop/slow down this neurodegeneration. Varenicline is an anti-smoking drug and has the potential to prevent neurodegeneration. Thus, the present study was designed to evaluate the effect of varenicline in animal models of PD. Methods Levodopa and haloperidol were administered in doses of 30 and 1 mg/kg, intraperitoneally (i.p.), respectively. Group 1 was administered haloperidol; groups 2, 3 and 4 were administered haloperidol along with varenicline in doses of 0.5, 1.5 and 2.5 mg/kg, i.p., respectively and group 5 was administered levodopa along with haloperidol. Varenicline was administered daily, 30 min prior to the administration of haloperidol. Varenicline was administered for the first 8 days, and then from the 9th day until the 15th day. Behavioral assessment (rotarod and catalepsy tests) was performed on days 9 and 15. Assessment of striatal dopamine levels and histopathology were also performed. Results In the haloperidol-treated groups, significant decrease in latency to fall off (on rotarod) and increase in catalepsy duration (in catalepsy test) were observed as compared to the control group. In the levodopa-treated group, significant increase in latency to fall off the rotarod and significant decrease in catalepsy duration were observed as compared to the haloperidol-treated groups. Further, on day 9, varenicline (2.5 mg/kg) significantly increased the latency to fall off the rotarod, while varenicline (0.5 and 1.5 mg/kg) did not cause any significant change in latency to fall off the rotarod as compared to the haloperidol-treated group. On day 15, significant increase in latency to fall off the rotarod was observed in varenicline (at all doses) as compared to the haloperidol-treated group. In the catalepsy test, the varenicline-treated (at all doses) groups showed significant decrease in duration of catalepsy on day 9 and day 15 as compared to the haloperidol-treated group. Significant decrease in striatal dopamine levels was observed among the haloperidol-treated groups as compared to the control group. Further, varenicline-treated (at all doses) and levodopa-treated groups showed significant increase in striatal dopamine levels when compared with the haloperidol-treated group. In histology, varenicline (0.5 mg/kg) showed moderate decrease in neurons, while varenicline (1.5 and 2.5 mg/kg) showed mild decrease in neurons. However, the levodopa-treated group did not show any significant decrease in neurons. Thus, varenicline has shown promising results and has provided novel strategy for the treatment of PD.

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