Sex-linked and autosomal microsatellites provide new insights into island populations of the tammar wallaby.

The emerging availability of microsatellite markers from mammalian sex chromosomes provides opportunities to investigate both male- and female-mediated gene flow in wild populations, identifying patterns not apparent from the analysis of autosomal markers alone. Tammar wallabies (Macropus eugenii), once spread over the southern mainland, have been isolated on several islands off the Western Australian and South Australian coastlines for between 10,000 and 13,000 years. Here, we combine analyses of autosomal, Y-linked and X-linked microsatellite loci to investigate genetic variation in populations of this species on two islands (Kangaroo Island, South Australia and Garden Island, Western Australia). All measures of diversity were higher for the larger Kangaroo Island population, in which genetic variation was lowest at Y-linked markers and highest at autosomal markers (θ=3.291, 1.208 and 0.627 for autosomal, X-linked and Y-linked data, respectively). Greater relatedness among females than males provides evidence for male-biased dispersal in this population, while sex-linked markers identified genetic lineages not apparent from autosomal data alone. Overall genetic diversity in the Garden Island population was low, especially on the Y chromosome where most males shared a common haplotype, and we observed high levels of inbreeding and relatedness among individuals. Our findings highlight the utility of this approach for management actions, such as the selection of animals for translocation or captive breeding, and the ecological insights that may be gained by combining analyses of microsatellite markers on sex chromosomes with those derived from autosomes.

Molecular cytogenetic map of the central bearded dragon, Pogona vitticeps (Squamata: Agamidae).

Reptiles, as the sister group to birds and mammals, are particularly valuable for comparative genomic studies among amniotes. The Australian central bearded dragon (Pogona vitticeps) is being developed as a reptilian model for such comparisons, with whole-genome sequencing near completion. The karyotype consists of 6 pairs of macrochromosomes and 10 pairs microchromosomes (2n = 32), including a female heterogametic ZW sex microchromosome pair. Here, we present a molecular cytogenetic map for P. vitticeps comprising 87 anchor bacterial artificial chromosome clones that together span each macro- and microchromosome. It is the first comprehensive cytogenetic map for any non-avian reptile. We identified an active nucleolus organizer region (NOR) on the sub-telomeric region of 2q by mapping 18S rDNA and Ag-NOR staining. We identified interstitial telomeric sequences in two microchromosome pairs and the W chromosome, indicating that microchromosome fusion has been a mechanism of karyotypic evolution in Australian agamids within the last 21 to 19 million years. Orthology searches against the chicken genome revealed an intrachromosomal rearrangement of P. vitticeps 1q, identified regions orthologous to chicken Z on P. vitticeps 2q, snake Z on P. vitticeps 6q and the autosomal microchromosome pair in P. vitticeps orthologous to turtle Pelodiscus sinensis ZW and lizard Anolis carolinensis XY. This cytogenetic map will be a valuable reference tool for future gene mapping studies and will provide the framework for the work currently underway to physically anchor genome sequences to chromosomes for this model Australian squamate.

[Improving the quality of compounded medicines through self-assessment: proof of concept]. / Améliorer la qualité des préparations magistrates par l'autocontrôle: proof of concept.

A systematic quality control of compounded medicines, and an associated guidance of community pharmacists, was identified as a complementary opportunity to improve and guarantee the quality of compounded medicines. Before implementing this on a national scale, a pilot project was organized. Fifty pharmacies prepared the same formula and had it checked regarding labelling, preparation reports and analytical parameters. This proof of concept demonstrated that the organisation of quality control of compounded medicines by the professional body itself is feasible. Such audits fit well in de quality assurance systems in place in community pharmacy, where any corrective measures are properly documented and implemented. This form of self-regulation has a preventive character for detecting defects and contributes to improving the quality of the preparations and thus to the patient safety.

Extension, single-locus conversion and physical mapping of sex chromosome sequences identify the Z microchromosome and pseudo-autosomal region in a dragon lizard, Pogona vitticeps.

Distribution of temperature-dependent sex determination (TSD) and genotypic sex determination (GSD) across the phylogeny of dragon lizards implies multiple independent origins of at least one, and probably both, modes of sex determination. Female Pogona vitticeps are the heterogametic sex, but ZZ individuals reverse to a female phenotype at high incubation temperatures. We used reiterated genome walking to extend Z and W chromosome-linked amplified fragment length polymorphism (AFLP) markers, and fluorescence in situ hybridization for physical mapping. One extended fragment hybridized to both W and Z microchromosomes, identifying the Z microchromosome for the first time, and a second hybridized to the centromere of all microchromosomes. W-linked sequences were converted to a single-locus PCR sexing assay. P. vitticeps sex chromosome sequences also shared homology with several other Australian dragons. Further physical mapping and isolation of sex-specific bacterial artificial chromosome clones will provide insight into the evolution of sex determination and sex chromosomes in GSD and TSD dragon lizards.

Sex chromosome evolution in lizards: independent origins and rapid transitions.

Reptiles epitomize the variability of reproductive and sex determining modes and mechanisms among amniotes. These modes include gonochorism (separate sexes) and parthenogenesis, oviparity, viviparity, and ovoviviparity, genotypic sex determination (GSD) with male (XX/XY) and female (ZZ/ZW) heterogamety and temperature-dependent sex determination (TSD). Lizards (order Squamata, suborder Sauria) are particularly fascinating because the distribution of sex-determining mechanisms shows no clear phylogenetic segregation. This implies that there have been multiple transitions between TSD and GSD, and between XY and ZW sex chromosome systems. Approximately 1,000 species of lizards have been karyotyped and among those, fewer than 200 species have sex chromosomes, yet they display remarkable diversity in morphology and degree of degeneration. The high diversity of sex chromosomes as well as the presence of species with TSD, imply multiple and independent origins of sex chromosomes, and suggest that the mechanisms of sex determination are extremely labile in lizards. In this paper, we review the current state of knowledge of sex chromosomes in lizards and the distribution of sex determining mechanisms and sex chromosome forms within and among families. We establish for the first time an association between the occurrence of female heterogamety and TSD within lizard families, and propose mechanisms by which female heterogamety and TSD may have co-evolved. We suggest that lizard sex determination may be much more the result of an interplay between sex chromosomes and temperature than previously thought, such that the sex determination mode is influenced by the nature of heterogamety as well as temperature sensitivity and the stage of sex chromosome degeneration.

[Drug related problems pharmacists encounter when a patient is discharged from hospital]. / Problématique des médicaments à prendre par les patients sortant de l'hôpital: etude réalisée auprès de pharmaciens d'officine flamands.

AIMS: To explore drug related problems a community pharmacist encounters when a patient is discharged from hospital. The study also investigates which information from the hospital reaches the community pharmacy. METHODS: A validated survey was presented, by community pharmacists, to patients or their family after hospital discharge, between the 1st of December 2007 and the 29th of February 2008. The survey contained questions on 4 items: patient characteristics--discharge medication--information received from the hospital--drug related problems and pharmacists interventions. Analyses were done with SPSS 16.0. MAIN RESULTS: 82 community pharmacists participated. 261 patients were included. Only 25% of the patients collected their medication from the pharmacy themselves. On discharge, patients on average received two additional drugs, compared to the pre-hospital situation. 69% received a medication chart, but less than half of them brought this chart along when visiting the pharmacy. Only 9% got computer-generated prescriptions from the hospital and < 3% received a letter of referral addressed to their pharmacist. In 33% of the cases the pharmacists noticed one or more problems concerning the medication prescribed after hospital discharge. The chance to detect a problem increased significantly when the chart was brought to the pharmacy (p=0.033). In case of observed problems, the community pharmacist succeeded to reach the treating specialist by phone in less than one third of those cases. CONCLUSION: The results foster the discussion on the need for a better seamless care and the role clinical and community pharmacists could play in this care model.

Short bowel syndrome: difficulties of management in rural areas.

INTRODUCTION: The causes of short bowel syndrome are multiple, but most often in sub-Saharan Africa they result from extensive surgical resection that leaves less than 200 cm. Intestinal failure appears rapidly with a major hydroelectrolytic deficiency and malabsorption. Management requires parenteral nutrition that can be life-long. OBSERVATION: A 53 year-old patient underwent surgery in 1986 for peptic ulcer disease and recovered successfully. He was admitted in July 2015 for acute bowel obstruction of more than 8 hours duration. Intraoperative exploration showed irreversible ischemia in the small bowel, related to tight adhesions. An extensive resection leaving 110 cm of bowel was carried out. Postoperatively, nutritional monitoring and oral supplementation were prescribed and associated with proton pump inhibitors and antidiarrhea drugs. Parenteral feeding was not available. The postoperative period was characterized by temporary stability followed by a significant weight loss, then by two hospitalizations for severe malnutrition and intercurrent infection. Death occurred 7 months after the operation. CONCLUSION: Parenteral nutrition is essential in short bowel syndrome. Availability, especially for a long-term use, is a major problem in our context, and alternatives are rare.

Complications inattendues de la chirurgie: deux cas de brûlure par plaque de bistouri électrique.

There is a real risk of electrical accidents in the operating theatre, with the growing number of electrical, electronic and flammable liquids used. Electrocautery remains the most commonly used device for its electrosurgical effect of coagulation or tissue section. When it is defective or misplaced on a small area of the skin, it can cause a typically deep, slow healing skin burn. It adds an unexpected iatrogenic morbidity to the initial condition, with devastating consequences for the patient, the surgeon and sometimes the hospital. We report two cases of cutaneous burn by the neutral plate that occurred intraoperatively when using electrocautery in monopolar mode, and discuss etiology, clinical and prevention aspects.

Serotonin reuptake inhibition by citalopram in rat strains differing for their emotionality.

Acute administration of the selective serotonin (5-HT) reuptake inhibitor (SSRI), citalopram (1-10 mg/kg, i.p. 1 h before an elevated plus-maze test), to Spontaneously Hypertensive rats (SHRs), Lewis (LEW) rats, and Wistar-Kyoto (WKY) rats, i.e., rat strains differing for their emotionality, promoted anxiety, and/or hypoactivity, except in WKY rats. In the three strains, such a pretreatment increased central 5-HT levels and/or decreased 5-hydroxyindoleacetic acid levels. Hippocampal, but not midbrain or striatal, [3H]citalopram binding at 5-HT transporters was lower in WKY rats than in SHRs. However, neither [3H]5-HT reuptake kinetics nor the potencies of citalopram (1-1000 nM) to inhibit [3H]5-HT reuptake into hippocampal and striatal synaptosomes differed between strains. This was confirmed in vivo by means of microdialysis in the hippocampus of freely moving rats. Thus, although LEW rats displayed a 3-4 fold higher baseline level of extracellular 5-HT in the hippocampus, compared with SHRs and WKY rats, local perfusion with 1 microM citalopram promoted relative increases in extracellular 5-HT levels over baseline that were similar in all strains. Lastly, acute i.p. administration of 3.3 mg/kg citalopram (1 h beforehand) decreased to similar extents [3H]5-HT reuptake into hippocampal synaptosomes from SHRs and WKY rats. This study indicates that genetic differences in the behavioural responses to SSRIs may involve 5-HT transporter-independent mechanisms.

Effect of bupropion on hippocampal neurotransmitters and on peripheral hormonal concentrations in the rat.

The purpose of the present study was to administer an acute dose of the dual dopamine norepinephrine reuptake blocker bupropion in freely moving rats and to monitor the extracellular neurotransmitter concentrations in the hippocampus via in vivo microdialysis and the peripheral hormonal concentrations via catheterization. A microdialysis probe was inserted in the hippocampus, and samples for serotonin, dopamine, and norepinephrine were collected every 20 min before and after the injection of 17 mg/kg of bupropion, for a total sampling time of 180 min. A catheter was placed in the vena femoralis of the second group of rats, and blood samples were collected before and after bupropion injection for quantification of growth hormone, prolactin, corticosterone, adrenocorticotropin hormone, and beta-endorphins. All neurotransmitter levels (dopamine, norepinephrine, and serotonin) significantly increased after bupropion injection. This was accompanied by a significant decrease in prolactin concentrations, whereas the other hormones showed no statistically significant variation. It can, therefore, be concluded that, although bupropion has dual reuptake proprieties, the observed effects both at the central and at the peripheral level seem to be ruled by the dopaminergic system.

The analysis of excitatory, inhibitory and other amino acids in rat brain microdialysates using microbore liquid chromatography.

Three microbore liquid chromatography (LC) assays for determination of amino acids in rat brain dialysates are described: one for separation of amino acids by gradient elution and electrochemical detection, one for analysis of GABA by isocratic elution and electrochemical detection, and one for fast measurement of glutamate and aspartate by gradient elution and fluorescence detection. The assays are reliable, reproducible and sensitive. In comparison with conventional LC, a 5-fold increase in sensitivity was obtained for GABA. Optimization of the derivatization chemistry and the microbore LC system are discussed, as well as important practical aspects.

In vitro and in vivo microdialysis calibration for the measurement of carbamazepine and its metabolites in rat brain tissue using the internal reference technique.

Microdialysis, as in vivo sampling technique, can be used for determining exogenous compounds in the extracellular fluid of freely moving animals and in humans. Usually, calibration of the microdialysis probe is determined by in vitro relative recovery (RR) (dialysate extraction fraction). However, due to different diffusion properties of the compound in tissue, the RR in vivo is different from the RR in vitro. In this study, the evaluation of the internal reference technique as in vivo calibration method was established. To determine the RR in vivo, the relative loss (RL) was defined as the loss of a compound from the perfusate. RL was determined in vitro and in vivo by adding an internal standard (IS) to the perfusate. This internal reference technique was applied for the determination of carbamazepine (CBZ) and its 2 major metabolites, carbamazepine-10,11-epoxide (CBZ-EPO) and trans-10,11-dihydroxy-10,11-dihydro-carbamazepine (CBZ-DIOL) using 2-methyl-5H-dibenz(b,f)azepine-5-carboxamide (m-CBZ) as IS. In vitro and in vivo, the loss of m-CBZ and the recovery of CBZ are identical. The ratios of the RR of CBZ-EPO and CBZ-DIOL to the RL of m-CBZ are constant, in vitro and in vivo. Therefore, m-CBZ can be used as IS for CBZ, CBZ-EPO and CBZ-DIOL determinations in brain tissue. It is shown that the internal reference technique is a useful method to estimate the true concentration of exogenous compounds in the extracellular space of tissues.

Characterization of the extracellular serotonin release in the substantia nigra of the freely moving rat using microdialysis.

The characteristics of the serotonin release were investigated in the substantia nigra (SN) of the freely moving rat using microdialysis. We also examined whether the delay between surgery and microdialysis experiments might influence these characteristics by implanting rats with a guide cannula 1 or 2 days prior to microdialysis experiments. In the first group, the tissue was not punctured until the microdialysis probe was inserted the evening before the experiment. In the second group, the nigral tissue was punctured with an extended obturator which was then replaced by a microdialysis probe the evening before the experiment. After administration of 60 mM K+ a more pronounced increase in serotonin was observed in the first group (260%) compared to the second group (159%). Calcium-free and tetrodotoxin (TTX, a sodium channel blocker) (1 microM) perfusion reduced extracellular serotonin to respectively 77% and 80% in the first group and 70% and 64% in the second group. These results suggest that vesicular release of nigral serotonin only occurs partially in this region and that minimizing the damage caused by implantation of the probe results only in 10% more vesicular release of serotonin. However, blockade of the serotonin reuptake carrier caused more TTX sensitivity of the serotonin release. Also, stimulation of the dorsal raphe by locally perfusing 60 mM K+ decreased serotonin in the SN, confirming the anatomical and functional link between both areas.

Effect of M1- and M2-muscarinic drugs on striatal dopamine release and metabolism: an in vivo microdialysis study comparing normal and 6-hydroxydopamine-lesioned rats.

Microdialysis was used to study the effect of M1 and M2 selective agonists and antagonists on striatal dopamine release and metabolism. Microdialysis probes were implanted, under anesthesia, in the left and the right striatum of the normal rats and in the normal and denervated striatum of the nigral 6-hydroxydopamine-lesioned rats. Dopamine (DA), 3,4-dihydroxyphenylacetic acid (DOPAC) and homovanillic acid (HVA) were determined by liquid chromatography and electrochemical detection. The different drugs were infused through the dialysis probe during 40 min. Pirenzepine (5 microM), a selective M1 antagonist, produced a significant decrease in DA release in the normal and the 6-hydroxydopamine-lesioned rats, with no significant difference between both groups. Methoctramine, a selective M2 antagonist, produced a dose-dependent increase in DA release between 20 and 200 microM in the normal rats, with no significant effect on DOPAC and HVA. Infusing 75 microM methoctramine produced a significant increase in DA release with a more pronounced effect in the intact animals compared to the 6-hydroxydopamine-lesioned animals. The non-selective agonist carbachol produced a decrease in dopamine release after infusion of 50 microM (M2 effect) and an increase in dopamine release after infusion of 50 mM (M1 effect) in the normal rats. Infusing 50 microM carbachol in the denervated striatum, produced a slight increase in DA release. Our data suggest that presynaptic M1-muscarinic receptors enhance and M2-muscarinic receptors inhibit DA release in the striatum of the rat; and that 3 weeks after 6-hydroxydopamine lesioning there may be a normalisation of the number of M1-receptors with a loss of M2-receptors at the denervated side.

Neostigmine influences the L-dopa-induced extracellular dopamine levels in the striatum.

Using in vivo microdialysis in freely moving rats, we show that the addition to the dialysis perfusion fluid of the acetylcholinesterase inhibitor neostigmine influences the decarboxylation of levodopa (L-dopa). Continuous perfusion of neostigmine (10, 50 and 100 nM) in striatum attenuated the L-dopa-induced dopamine release in a dose-dependent manner. This effect suggests that changes in magnitude of drug responses may occur when an acetylcholinesterase inhibitor is included in the perfusion solution. Results obtained under these circumstances should be carefully interpreted concerning the pharmacological effects of other drugs when used concomitantly with neostigmine.

Dopaminergic regulation of serotonin release in the substantia nigra of the freely moving rat using microdialysis.

The functional regulation by dopamine (DA) receptors of serotonin (5-HT) release from the rat substantia nigra (SN) was investigated using in vivo microdialysis. A D1- and D2-receptor-mediated inhibition of nigral 5-HT release was demonstrated in this study. Continuous administration of the D1-receptor agonist CY 208243 (10 microM) through the probe did not alter extracellular DA nor 5-HT from the SN, whereas intranigral administration of the D1-receptor antagonist SCH-23390 HCl (10 microM) significantly increased both DA (to 214%) and 5-HT release (to 168%) from the SN. Co-perfusion of the D1-receptor agonist and antagonist did not change nigral DA nor 5-HT release compared to perfusion of the antagonist alone. The continuous intranigral perfusion of the D2-receptor agonist, (-)-quinpirole HCl (1 microM) significantly decreased both DA ad 5-HT release to 71% and 78%, respectively. These decreases were abolished when the D2-receptor antagonist S(-)-sulpiride (10 microM) and the D2-receptor agonist (-)-quinpirole HCl (1 microM) were co-perfused. In contrast, the intranigral perfusion of the DA precursor, L-DOPA (5 microM; 1 h), significantly increased nigral and striatal 5-HT release to 202% and 155%, respectively. This enhanced nigral 5-HT release might not be receptor-mediated. The results of the present study suggest a D1 and D2 regulation of nigral 5-HT release, either directly mediated by DA receptors on nigral 5-HT terminals or indirectly by nigral GABA, Glu or Asp. Alternatively, the observed DA-5HT-interaction in the SN might not reflect a local interaction but might involve an interaction at the level of the serotonin cell body region, the dorsal raphe nuclei (DRN).

Neurochemical changes and laser Doppler flowmetry in the endothelin-1 rat model for focal cerebral ischemia.

Generalized neurotransmitter overflow into the extracellular space, after cerebral ischemia, has been suggested to contribute to subsequent neuronal death. This study aims to investigate the striatal release of the neurotransmitters dopamine (DA), glutamate (Glu) and gamma-aminobutyric acid (GABA) by means of microdialysis, in a rat model for focal transient cerebral ischemia. Ischemia was induced by the application of 120 pmol endothelin-1 (Et-1), adjacent to the middle cerebral artery (MCA) in freely moving rats. Ischemia produced a large increase in extracellular striatal DA concentrations (2400%), Glu (5500%) and GABA (800%) concentrations. Laser Doppler flowmetry in anaesthetized rats, indicated that the blood flow within the striatum decreased by 75+/-11%. The period of sustained drop of blood flow, was dose-dependently related to the concentration Et-1 injected. Histological analysis of brain slices, taken from anaesthetized and conscious animals, indicated a 500 pmol dose of Et-1 was required to produce a similar infarct in anaesthetized rats to a 120 pmol dose of Et-1 in freely moving rats. The immediate drop in striatal blood flow, and the prompt increase of extracellular DA, after the micro-application of Et-1, were quite striking. This suggests that the DA release, rather than the Glu overflow may be the primary event initiating the cascade of processes ultimately leading to cell death and neurological deficits.

Effects of tryptophan and/or acute running on extracellular 5-HT and 5-HIAA levels in the hippocampus of food-deprived rats.

The present microdialysis study has examined whether exercise-elicited increases in brain tryptophan availability (and in turn 5-HT synthesis) alter 5-HT release in the hippocampus of food-deprived rats. To this end, we compared the respective effects of acute exercise, administration of tryptophan, and the combination of both treatments, upon extracellular 5-HT and 5-hydroxyindoleacetic acid (5-HIAA) levels. All rats were trained to run on a treadmill before implantation of the microdialysis probe and 24 h of food deprivation. Acute exercise (12 m/min for 1 h) increased in a time-dependent manner extracellular 5-HT levels (maximal increase: 47%), these levels returning to their baseline levels within the first hour of the recovery period. Besides, exercise-induced increases in extracellular 5-HIAA levels did not reach significance. Acute administration of a tryptophan dose (50 mg/kg i.p.) that increased extracellular 5-HIAA (but not 5-HT) levels in fed rats, increased within 60 min extracellular 5-HT levels (maximal increase: 55%) in food-deprived rats. Whereas 5-HT levels returned toward their baseline levels within the 160 min that followed tryptophan administration, extracellular 5-HIAA levels rose throughout the experiment (maximal increase: 75%). Lastly, treatment with tryptophan (60 min beforehand) before acute exercise led to marked increases in extracellular 5-HT and 5-HIAA levels (maximal increases: 100% and 83%, respectively) throughout the 240 min that followed tryptophan administration. This study indicates that exercise stimulates 5-HT release in the hippocampus of fasted rats, and that a pretreatment with tryptophan (at a dose increasing extracellular 5-HT levels) amplifies exercise-induced 5-HT release.

Differential effects of restraint stress on hippocampal 5-HT metabolism and extracellular levels of 5-HT in streptozotocin-diabetic rats.

Streptozotocin (STZ)-elicited diabetes reduces central serotonin (5-hydroxytryptamine, 5-HT) synthesis/metabolism, but whether this reduction leads to decreased release of 5-HT has only scarcely been investigated. We have thus analysed the impact of STZ diabetes on hippocampal extracellular 5-HT levels both under basal conditions and during restraint stress, a procedure known to stimulate hippocampal 5-HT synthesis/metabolism and release. The pretreatment with STZ (3 weeks beforehand) and the 1 h restraint session respectively decreased and increased hippocampal 5-HT metabolism, as assessed by tissue analysis of 5-HT and 5-hydroxyindoleacetic acid. On the other hand, hippocampal microdialysis revealed no difference in basal levels of extracellular 5-HT levels in (conscious) vehicle- and STZ-pretreated rats, but a differential effect of restraint. Thus, extracellular 5-HT levels increased throughout restraint (maximal increase: 194%) in vehicle-, but not in STZ-pretreated rats. In the latter rat group, plasma corticosterone levels were, however, increased, thus indicating a significant aversiveness to stress. Lastly, because anxiety-related behaviours may be affected by hippocampal serotonergic systems, resting and restrained vehicle- and STZ-pretreated rats were compared (immediately after stress) in an elevated plus-maze of anxiety. Pretreatment with STZ reduced the percent number of open arm entries and the number of closed arm entries, indicating increased anxiety and reduced locomotor activity, respectively. Restraint tended to increase anxiety-related behaviours in all rats, but this trend never reached significance. Our results confirm that gross analyses of 5-HT metabolism do not yield information on 5-HT release, and suggest that the prevalence of diabetes among patients suffering affective disorders could be related to the lack of hippocampal serotonergic response to aversive stimuli.

Postischemic mild hypothermia reduces neurotransmitter release and astroglial cell proliferation during reperfusion after asphyxial cardiac arrest in rats.

The present study investigated whether postischemic mild hypothermia attenuates the ischemia-induced striatal glutamate (GLU) and dopamine (DA) release, as well as astroglial cell proliferation in the brain. Anesthetized rats were exposed to 8 min of asphyxiation, including 5 min of cardiac arrest. The cardiac arrest was reversed to restoration of spontaneous circulation (ROSC), by brief external heart massage and ventilation within a period of 2 min. After the insult and during reperfusion, the extracellular glutamate and dopamine overflow increased to, respectively, 3000% and 5000% compared with the baseline values in the normothermic group and resulted in brain damage, ischemic neurons and gliosis. However, when hypothermia was induced for a period of 60 min after the insult and restoration of spontaneous circulation, the glutamate and dopamine overflows were not significantly different from that in the sham group. Histological analysis of the brain showed that postischemic mild hypothermia reduced brain damage, ischemic neurons, as well as astroglial cell proliferation. Thus, postischemic mild hypothermia reduces the excitotoxic process, brain damage, as well as astroglial cell proliferation during reperfusion. Moreover, these results emphasize the trigger effect of dopamine on the excitotoxic pathway.