scholarly journals Paradoxical Emergence

2017 ◽  
Vol 126 (3) ◽  
pp. 482-494 ◽  
Author(s):  
Viviane S. Hambrecht-Wiedbusch ◽  
Duan Li ◽  
George A. Mashour
Keyword(s):  
Prefrontal Cortex ◽  
General Anesthesia ◽  
High Performance ◽  
Occipital Cortex ◽  
Brain Regions ◽  
Male Rats ◽  
Saline Control ◽  
Guide Cannula ◽  
Isoflurane Anesthesia ◽  
Cholinergic Tone

Abstract Background Promoting arousal by manipulating certain brain regions and/or neurotransmitters has been a recent research focus, with the goal of trying to improve recovery from general anesthesia. The current study tested the hypothesis that a single subanesthetic dose of ketamine during isoflurane anesthesia would increase cholinergic tone in the prefrontal cortex and accelerate recovery. Methods Adult male rats were implanted with electroencephalography electrodes (frontal, parietal, and occipital cortex) and a microdialysis guide cannula targeted for the prefrontal cortex. After establishing general anesthesia with isoflurane, animals were randomly assigned to receive a saline control or ketamine injection. When isoflurane was discontinued nearly 90 min after drug or saline administration, recovery from anesthesia was measured by experimenters and blinded observers. During the entire experiment, electrophysiologic signals were recorded and acetylcholine was quantified by high-performance liquid chromatography with electrochemical detection. Results A single dose of subanesthetic ketamine caused an initial 125% increase in burst suppression ratio (last isoflurane sample: 37.48 ± 24.11% vs. isoflurane after ketamine injection: 84.36 ± 8.95%; P < 0.0001), but also a significant 44% reduction in emergence time (saline: 877 ± 335 s vs. ketamine: 494 ± 108 s; P = 0.0005; n = 10 per treatment). Furthermore, ketamine caused a significant 317% increase in cortical acetylcholine release (mean after ketamine injection: 0.18 ± 0.16 pmol vs. ketamine recovery: 0.75 ± 0.41 pmol; P = 0.0002) after isoflurane anesthesia was discontinued. Conclusions Administration of subanesthetic doses of ketamine during isoflurane anesthesia increases anesthetic depth but—paradoxically—accelerates the recovery of consciousness, possibly through cholinergic mechanisms.

scholarly journals Caloric restriction modulates the monoaminergic system and metabolic hormones in aged rats

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Marta Portero-Tresserra ◽  
D. Rojic-Becker ◽  
C. Vega-Carbajal ◽  
G. Guillazo-Blanch ◽  
A. Vale-Martínez ◽  
...  
Keyword(s):  
Caloric Restriction ◽  
High Performance ◽  
Dietary Intervention ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Occipital Cortex ◽  
Brain Regions ◽  
Metabolic Parameters ◽  
Negative Effects ◽  
Brain Monoamine

Abstract Caloric restriction (CR) can attenuate the general loss of health observed during aging, being one of the mechanisms involved the reduction of hormonal alteration, such as insulin and leptin. This change could also prevent age-specific fluctuations in brain monoamines, although few studies have addressed the effects of CR on peripheral hormones and central neurotransmitters exhaustively. Therefore, the variations in brain monoamine levels and some peripheral hormones were assessed here in adult 4-month old and 24-month old male Wistar rats fed ad libitum (AL) or maintained on a 30% CR diet from four months of age. Noradrenaline (NA), dopamine (DA), serotonin (5-HT) and its metabolites were measured by high-performance liquid chromatography with electrochemical detection (HPLC-ED) in nine brain regions: cerebellum, pons, midbrain, hypothalamus, thalamus, hippocampus, striatum, frontal cortex, and occipital cortex. In addition, the blood plasma levels of hormones like corticosterone, insulin and leptin were also evaluated, as were insulin-like growth factor 1 and other basal metabolic parameters using enzyme-linked immunosorbent assays (ELISAs): cholesterol, glucose, triglycerides, albumin, low-density lipoprotein, calcium and high-density lipoprotein (HDLc). CR was seen to increase the NA levels that are altered by aging in specific brain regions like the striatum, thalamus, cerebellum and hypothalamus, and the DA levels in the striatum, as well as modifying the 5-HT levels in the striatum, hypothalamus, pons and hippocampus. Moreover, the insulin, leptin, calcium and HDLc levels in the blood were restored in old animals maintained on a CR diet. These results suggest that a dietary intervention like CR may have beneficial health effects, recovering some negative effects on peripheral hormones, metabolic parameters and brain monoamine concentrations.

The Key Locus of Common Response Inhibition Network for No-go and Stop Signals

2008 ◽  
Vol 20 (8) ◽  
pp. 1434-1442 ◽  
Author(s):  
Dongming Zheng ◽  
Tatsuro Oka ◽  
Hirokazu Bokura ◽  
Shuhei Yamaguchi
Keyword(s):  
Prefrontal Cortex ◽  
Response Inhibition ◽  
Error Detection ◽  
Response Competition ◽  
Occipital Cortex ◽  
Brain Regions ◽  
Stop Signal ◽  
Human Beings ◽  
Specific Effects ◽  
The Right

Response inhibition is one of the highest evolved executive functions of human beings. Previous studies revealed a wide variety of brain regions related to response inhibition, although some of them may not be directly related to inhibition but to task-specific effects or noninhibitory cognitive functions such as attention, response competition, or error detection. Here, we conducted event-related functional magnetic resonance imaging studies in which all subjects performed both stop-signal and go/no-go tasks in order to explore key neural correlates within the response inhibition network irrelevant to task designs and other cognitive processes. The successful inhibition in the stop-signal and go/no-go tasks, respectively, activated a set of predominantly right-lateralized hemispheric cortices. The common inhibitory regions across the two tasks included the right middle prefrontal cortex in addition to the right middle occipital cortex. Correlation analysis was carried out within these areas between intensity of activation and behavioral performance in the two tasks. Only the region located in the middle prefrontal cortex showed significant correlations in both tasks. We believe this region is the key locus for execution of response inhibition in the distributed inhibitory neural network.

scholarly journals Pioglitazone Ameliorates Neuron Loss in the Cortex after Aluminum-Treatment in Rats

2015 ◽  
Vol 2015 ◽  
pp. 1-8 ◽  
Author(s):  
Ali Rafati ◽  
Hajar Yazdani ◽  
Ali Noorafshan
Keyword(s):  
Prefrontal Cortex ◽  
Medial Prefrontal Cortex ◽  
Glial Cells ◽  
Structural Changes ◽  
Brain Regions ◽  
Male Rats ◽  
Neuron Loss ◽  
The Right ◽  
Al Treatment

The objective was evaluation of the effects of pioglitazone on medial prefrontal cortex (mPFC) of the rats exposed to aluminum (Al). Al induces structural changes in several brain regions, including mPFC. Pioglitazone is an agonist of peroxisomal proliferator activated receptor gamma. Male rats were randomly assigned to control, Al-treated (10 mg/kg/day), and Al + PIO-treated groups (Al+ 40 mg/kg/day). After 56 days, the right mPFCs were removed. Then, the volume of mPFC and its subdivisions, volume of vessels, and total number of neurons and glia were estimated using stereological methods. The results showed 13–38% decrease in the volume of the mPFC and its subdivisions, mainly in the infralimbic region (P<0.02). Besides, the volume of the vessels reduced by 47% after Al-treatment (P<0.02). The total number of the neurons and glial cells was also reduced (40% and 25%, resp.) in the Al-exposed rats in comparison to the control ones (P<0.02). Treatment of the animals with Al + PIO ameliorated the neuron loss and no improvement was seen in other parameters (P<0.02). It can be concluded that treatment of the rats with PIO could ameliorate the neuron loss in the mPFC of the Al-treated animals.

Reflecting upon Feelings: An fMRI Study of Neural Systems Supporting the Attribution of Emotion to Self and Other

2004 ◽  
Vol 16 (10) ◽  
pp. 1746-1772 ◽  
Author(s):  
Kevin N. Ochsner ◽  
Kyle Knierim ◽  
David H. Ludlow ◽  
Josh Hanelin ◽  
Tara Ramachandran ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Emotional State ◽  
Mixed Valence ◽  
Temporal Cortex ◽  
Superior Temporal Gyrus ◽  
Occipital Cortex ◽  
Brain Regions ◽  
Neural Systems ◽  
Emotional States ◽  
Self And Other

Understanding one's own and other individual's emotional states is essential for maintaining emotional equilibrium and strong social bonds. Although the neural substrates supporting reflection upon one's own feelings have been investigated, no studies have directly examined attributions about the internal emotional states of others to determine whether common or distinct neural systems support these abilities. The present study sought to directly compare brain regions involved in judging one's own, as compared to another individual's, emotional state. Thirteen participants viewed mixed valence blocks of photos drawn from the International Affective Picture System while whole-brain fMRI data were collected. Preblock cues instructed participants to evaluate either their emotional response to each photo, the emotional state of the central figure in each photo, or (in a baseline condition) whether the photo was taken indoors or outdoors. Contrasts indicated (1) that both self and other judgments activated the medial prefrontal cortex (MPFC), the superior temporal gyrus, and the posterior cingulate/precuneus, (2) that self judgments selectively activated subregions of the MPFC and the left temporal cortex, whereas (3) other judgments selectively activated the left lateral prefrontal cortex (including Broca's area) and the medial occipital cortex. These results suggest (1) that self and other evaluation of emotion rely on a network of common mechanisms centered on the MPFC, which has been hypothesized to support mental state attributions in general, and (2) that medial and lateral PFC regions selectively recruited by self or other judgments may be involved in attention to, and elaboration of, internally as opposed to externally generated information.

scholarly journals Hippocampal regenerative medicine: neurogenic implications for addiction and mental disorders

2021 ◽  
Author(s):  
Lee Peyton ◽  
Alfredo Oliveros ◽  
Doo-Sup Choi ◽  
Mi-Hyeon Jang
Keyword(s):  
Decision Making ◽  
Prefrontal Cortex ◽  
Executive Function ◽  
General Population ◽  
Mental Disorders ◽  
Psychiatric Illness ◽  
Neural Circuitry ◽  
Brain Regions ◽  
Neuropsychiatric Disease ◽  
Motivated Behavior

AbstractPsychiatric illness is a prevalent and highly debilitating disorder, and more than 50% of the general population in both middle- and high-income countries experience at least one psychiatric disorder at some point in their lives. As we continue to learn how pervasive psychiatric episodes are in society, we must acknowledge that psychiatric disorders are not solely relegated to a small group of predisposed individuals but rather occur in significant portions of all societal groups. Several distinct brain regions have been implicated in neuropsychiatric disease. These brain regions include corticolimbic structures, which regulate executive function and decision making (e.g., the prefrontal cortex), as well as striatal subregions known to control motivated behavior under normal and stressful conditions. Importantly, the corticolimbic neural circuitry includes the hippocampus, a critical brain structure that sends projections to both the cortex and striatum to coordinate learning, memory, and mood. In this review, we will discuss past and recent discoveries of how neurobiological processes in the hippocampus and corticolimbic structures work in concert to control executive function, memory, and mood in the context of mental disorders.

scholarly journals Central Noradrenergic Neurotransmission and Weight Loss 6 Months After Gastric Bypass Surgery in Patients with Severe Obesity

2021 ◽  
Author(s):  
J. Marvin Soeder ◽  
Julia Luthardt ◽  
Michael Rullmann ◽  
Georg A. Becker ◽  
Mohammed K. Hankir ◽  
...  
Keyword(s):  
Weight Loss ◽  
Gastric Bypass ◽  
Severe Obesity ◽  
Occipital Cortex ◽  
Brain Regions ◽  
General Tendency ◽  
Strong Positive Correlation ◽  
Reference Tissue ◽  
Efficient Treatment ◽  
Post Surgery

Abstract Purpose Roux-en-Y gastric bypass (RYGB) surgery is currently the most efficient treatment to achieve long-term weight loss in individuals with severe obesity. This is largely attributed to marked reductions in food intake mediated in part by changes in gut-brain communication. Here, we investigated for the first time whether weight loss after RYGB is associated with alterations in central noradrenaline (NA) neurotransmission. Materials and Methods We longitudinally studied 10 individuals with severe obesity (8 females; age 43.9 ± 13.1 years; body mass index (BMI) 46.5 ± 4.8 kg/m2) using (S,S)-[11C]O-methylreboxetine and positron emission tomography to estimate NA transporter (NAT) availability before and 6 months after surgery. NAT distribution volume ratios (DVR) were calculated by volume-of-interest analysis and the two-parameter multilinear reference tissue model (reference region: occipital cortex). Results The participants responded to RYGB surgery with a reduction in BMI of 12.0 ± 3.5 kg/m2 (p < 0.001) from baseline. This was paralleled by a significant reduction in DVR in the dorsolateral prefrontal cortex (pre-surgery 1.12 ± 0.04 vs. post-surgery 1.07 ± 0.04; p = 0.019) and a general tendency towards reduced DVR throughout the brain. Furthermore, we found a strong positive correlation between pre-surgery DVR in hypothalamus and the change in BMI (r = 0.78; p = 0.01). Conclusion Reductions in BMI after RYGB surgery are associated with NAT availability in brain regions responsible for decision-making and homeostasis. However, these results need further validation in larger cohorts, to assess whether brain NAT availability could prognosticate the outcome of RYGB on BMI. Graphical abstract

scholarly journals Convergence of heteromodal lexical retrieval in the lateral prefrontal cortex

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Alexander A. Aabedi ◽  
Sofia Kakaizada ◽  
Jacob S. Young ◽  
Jasleen Kaur ◽  
Olivia Wiese ◽  
...  
Keyword(s):  
Prefrontal Cortex ◽  
Picture Naming ◽  
Cognitive Rehabilitation ◽  
Tumor Model ◽  
Brain Regions ◽  
Support Vector ◽  
Lexical Retrieval ◽  
Lateral Prefrontal Cortex ◽  
Lesion Symptom Mapping ◽  
Single Construct

AbstractLexical retrieval requires selecting and retrieving the most appropriate word from the lexicon to express a desired concept. Few studies have probed lexical retrieval with tasks other than picture naming, and when non-picture naming lexical retrieval tasks have been applied, both convergent and divergent results emerged. The presence of a single construct for auditory and visual processes of lexical retrieval would influence cognitive rehabilitation strategies for patients with aphasia. In this study, we perform support vector regression lesion-symptom mapping using a brain tumor model to test the hypothesis that brain regions specifically involved in lexical retrieval from visual and auditory stimuli represent overlapping neural systems. We find that principal components analysis of language tasks revealed multicollinearity between picture naming, auditory naming, and a validated measure of word finding, implying the existence of redundant cognitive constructs. Nonparametric, multivariate lesion-symptom mapping across participants was used to model accuracies on each of the four language tasks. Lesions within overlapping clusters of 8,333 voxels and 21,512 voxels in the left lateral prefrontal cortex (PFC) were predictive of impaired picture naming and auditory naming, respectively. These data indicate a convergence of heteromodal lexical retrieval within the PFC.

scholarly journals Comparison of Activation in the Prefrontal Cortex of Native Speakers of Mandarin by Ability of Japanese as a Second Language Using a Novel Speaking Task

Healthcare ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 412
Author(s):  
Li Cong ◽  
Hideki Miyaguchi ◽  
Chinami Ishizuki
Keyword(s):  
Second Language ◽  
Prefrontal Cortex ◽  
Cognitive Load ◽  
Near Infrared ◽  
Native Speakers ◽  
Brain Activation ◽  
Brain Regions ◽  
Strong Inhibition ◽  
Functional Near Infrared Spectroscopy ◽  
High Level

Evidence shows that second language (L2) learning affects cognitive function. Here in this work, we compared brain activation in native speakers of Mandarin (L1) who speak Japanese (L2) between and within two groups (high and low L2 ability) to determine the effect of L2 ability in L1 and L2 speaking tasks, and to map brain regions involved in both tasks. The brain activation during task performance was determined using prefrontal cortex blood flow as a proxy, measured by functional near-infrared spectroscopy (fNIRS). People with low L2 ability showed much more brain activation when speaking L2 than when speaking L1. People with high L2 ability showed high-level brain activation when speaking either L2 or L1. Almost the same high-level brain activation was observed in both ability groups when speaking L2. The high level of activation in people with high L2 ability when speaking either L2 or L1 suggested strong inhibition of the non-spoken language. A wider area of brain activation in people with low compared with high L2 ability when speaking L2 is considered to be attributed to the cognitive load involved in code-switching L1 to L2 with strong inhibition of L1 and the cognitive load involved in using L2.

Sex Differences of Hepatic Conjugation of Bilirubin Determine its Maximal Biliary Excretion in Non-Anaesthetized Male and Female Rats

1983 ◽  
Vol 64 (1) ◽  
pp. 85-90 ◽  
Author(s):  
Maurizio Muraca ◽  
Jan De Groote ◽  
Johan Fevery
Keyword(s):  
Biliary Excretion ◽  
High Performance ◽  
Relative Proportion ◽  
Female Rats ◽  
Male Rats ◽  
Transferase Activity ◽  
Hepatic Transport ◽  
Male And Female Rats ◽  
Udp Glucuronosyltransferase ◽  
Rate Limiting

1. Hepatic bilirubin UDP-glucuronosyltransferase activity was higher in female than in male rats; gonadectomy decreased enzyme activity in females and increased it in males. This sex difference in bilirubin conjugation was further used to evaluate the effect of differences in conjugation on the maximal biliary excretion of bilirubin in the non-anaesthetized rat. 2. After infusion of bilirubin, the maximal biliary excretory rate (Tm) and maximal concentration of bilirubin in bile were respectively 70% and 40% higher in female than in male rats; these values were decreased in females after ovariectomy and increased in males after orchiectomy. A linear relationship was found (r = 0.86; P < 0.001) between bilirubin Tm and hepatic bilirubin UDP-glucuronosyltransferase activity in the four groups of rats, suggesting that conjugation was the rate-limiting step for the maximal hepatic transport of bilirubin. 3. At the end of bilirubin infusion, bilirubin conjugates in serum, determined by alkaline methanolysis and high-performance liquid chromatography, ranged from 0.5 to 1.4% of total bilirubin. Therefore no significant reflux of conjugated bilirubin occurred during saturation of the hepatic transport of the pigment, once more suggesting that the secretory step was not rate-limiting. 4. The composition of bilirubin conjugates in bile was similar in the four groups of rats, despite significant differences in transferase activity. This suggests that the relative proportion of bilirubin mono- and di-conjugates in bile is affected by factors other than transferase activity alone. Relatively more monoconjugates were excreted under the bilirubin load than in basal conditions.

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