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pregnancy.longitudinal prospective human studies will be needed to evaluate the consequences of caffeine consumption during effects of adenosine receptor antagonists including caffeine on brain development in humans. Retrospective and neuronal types as well as impaired memory on certain types of memory tests. This study raises questions about the that adult offspring of pregnant mice treated with adenosine receptor antagonists had reduced numbers of certain antagonists were more susceptible to seizures when exposed to a seizure-inducing agent. They further demonstrated into target regions. They then showed that 1-week-old offspring of pregnant mice treated with adenosine receptor delayed the migration of specific populations of neurons during brain maturation, resulting in their delayed insertion They found that caffeine or an adenosine receptor antagonist that specifically blocks type 2A adenosine receptors added caffeine to the drinking water of female mice throughout pregnancy and lactation. Monique Esclapez, 1,2 † Christophe Bernard 1,2 * † Consumption of certain substances during pregnancy can interfere with brain development, leading to deleterious long-term neurological and cognitive impairments in offspring. To test whether modulators of adenosine receptors affect neural development, we exposed mouse dams to a subtype-selective adenosine type 2A receptor (A 2A R) antagonist or to caffeine, a naturally occurring adenosine receptor antagonist, during pregnancy and lactation. We observed delayed migration and insertion of g-aminobutyric acid (GABA) neurons into the hippocampal circuitry during the first postnatal week in offspring of dams treated with the A 2A R antagonist or caffeine. This was associated with increased neuronal network excitability and increased susceptibility to seizures in response to a seizure-inducing agent. Adult offspring of mouse dams exposed to A 2A R antagonists during pregnancy and lactation displayed loss of hippocampal GABA neurons and some cognitive deficits. These results demonstrate that exposure to A 2A R antagonists including caffeine during pregnancy and lactation in rodents may have adverse effects on the neural development of their offspring.

Tyrosine hydroxylase (TH)-immunoreactive (ir) neurones are detected in the striatum of animals after dopamine depletion and also in human parkinsonian patients. Although there is extensive evidence for TH-ir neurones in the lesioned rodent striatum, there are few details regarding the molecular phenotype of these neurones, regulation of their TH expression after l-3,4-dihydroxyphenylalanine (L-DOPA) treatment and their function. In the present study, we examined the time-course of appearance of TH-ir neurones in the mouse striatum after 6-hydroxydopamine (6-OHDA) lesion and determined their molecular phenotype. We found that TH-ir neurones appeared in the striatum as early as 3 days after a 6-OHDA lesion. By 1 week after the lesion, the number of TH-ir neurones started to decrease and this decrease progressed significantly over time. Treatment with L-DOPA increased both the number of TH-ir neurones and the intensity of their immunolabelling. The TH-ir neurones that appear after the 6-OHDA lesion in the striatum are not newly generated cells as they did not incorporate 5-bromo-2-deoxyuridine. We found that the vast majority of TH-ir neurones colocalized with dynorphin and enkephalin, suggesting that they are projection neurones of the direct and indirect striatal output pathways. TH-ir neurones did not express the dopamine transporter but half of them expressed amino acid decarboxylase, an enzyme required for dopamine synthesis. Finally, striatal TH-ir neurones are functionally active, expressing the neuronal activation marker FosB in response to L-DOPA treatment. Promotion of these striatal TH-ir neurones may be beneficial in Parkinson's disease, particularly in the early stages when dopamine denervation is incomplete.

The vast majority of cortical GABAergic neurons can be defined by parvalbumin, somatostatin or calretinin expression. In most mammalians, parvalbumin and somatostatin interneurons have constant proportions, each representing 5–7% of the total neuron number. In contrast, there is a threefold increase in the proportion of calretinin interneurons, which do not exceed 4% in rodents and reach 12% in higher order areas of primate cerebral cortex. In rodents, almost all parvalbumin and somatostatin interneurons originate from the medial part of the subpallial proliferative structure, the ganglionic eminence (GE), while almost all calretinin interneurons originate from its caudal part. The spatial pattern of cortical GABAergic neurons origin from the GE is preserved in the monkey and human brain. However, it could be expected that the evolution is changing developmental rules to enable considerable expansion of calretinin interneuron population. During the early fetal period in primates, cortical GABAergic neurons are almost entirely generated in the subpallium, as in rodents. Already at that time, the primate caudal ganglionic eminence (CGE) shows a relative increase in size and production of calretinin interneurons. During the second trimester of gestation, that is the main neurogenetic stage in primates without clear correlates found in rodents, the pallial production of cortical GABAergic neurons together with the extended persistence of the GE is observed. We propose that the CGE could be the main source of calretinin interneurons for the posterior and lateral cortical regions, but not for the frontal cortex. The associative granular frontal cortex represents around one third of the cortical surface and contains almost half of cortical calretinin interneurons. The majority of calretinin interneurons destined for the frontal cortex could be generated in the pallium, especially in the newly evolved outer subventricular zone that becomes the main pool of cortical progenitors.

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IntroductionThe process of aging is usually followed by cognitive decline that is characterized by impairments in a variety of tests for spatial memory [1][2][3][4][5][6]. It is suggested that the anatomical substrate for these impairments is to be found in age-related changes that appear mostly in hippocampal formation [1][2][3][7][8][9][10][11][12][13]. In particular, the dendritic trees of dentate granular cells are the main receptive field for afferent projections in the hippocampus. These cells receive sensory information from neocortical areas through the perforant pathway synapses from neurons in the superficial layers of the entorhinal cortex [14, 15]. Numerous anatomical studies indicate that the dentate gyrus of aged rats shows dendritic atrophy, partial deafferentation, concomitant loss of synapses, astrocyte hypertrophy [16][17][18][19][20][21][22][23][24], as well as decrease in neurogenesis in comparison with young animals [25]. [26]. Neurochemical studies showed decrease in neurotrophin levels [27, 28]. Electrophysiological data have shown a decrease in the NMDAN (Nmethyl-D-aspartic acid)-receptor-mediated response at perforant path synapses onto dentate gyrus granule cells, and impairments of synaptic plasticity, which include deficits in the induction and maintenance of long-term potentiation, lower thresholds for depotentiation and long-term depressionSince

This study was designed in a rat model to determine the hallmarks of possible permanent behavioral and structural brain alterations after a single moderate hypoxic insult. Eighty-two Wistar Han (RccHan: WIST) rats were randomly subjected to hypoxia (pO2 73 mmHg/2 h) or normoxia at the first postnatal day. The substantially increased blood lactate, a significantly decreased cytochrome-C-oxygenase expression in the brain, and depleted subventricular zone suggested a high vulnerability of subset of cell populations to oxidative stress and consequent tissue response even after a single, moderate, hypoxic event. The results of behavioral tests (open-field, hole-board, social-choice, and T-maze) applied at the 30–45th and 70–85th postnatal days revealed significant hyperactivity and a slower pace of learning in rats subjected to perinatal hypoxia. At 3.5 months after hypoxic insult, the histochemical examination demonstrated a significantly increased number of specific extracellular matrix—perineuronal nets and increased parvalbumin expression in a subpopulation of interneurons in the medial and retrosplenial cingulate cortex of these animals. Conclusively, moderate perinatal hypoxia in rats causes a long-lasting reorganization of the connectivity in the cingulate cortex and consequent alterations of related behavioral and cognitive abilities. This non-invasive hypoxia model in the rat successfully and complementarily models the moderate perinatal hypoxic injury in fetuses and prematurely born human babies and may enhance future research into new diagnostic and therapeutic strategies for perinatal medicine.