Alpha1- and Beta-norepinephrinergic receptors of dorsomedial and ventromedial hypothalamic nuclei modulate panic attack-like defensive behaviour elicited by diencephalic GABAergic neurotransmission disinhibition.

Gamma-aminobutyric acid (GABA) disinhibition in medial hypothalamus (MH) nuclei of rats elicits some defensive reactions that are considered panic attack-like behaviours. Recent evidence showed that the norepinephrine-mediated system modulates fear-related defensive behaviours organised by MH neurons at least in part via noradrenergic receptors recruitment on midbrain tegmentum. However, it is unknown whether noradrenergic receptors of the MH also modulate the panic attack-like reactions. The aim of this work was to investigate the distribution of noradrenergic receptors in MH, and the effects of either α1-, α2- or ß-noradrenergic receptors blockade in the MH on defensive behaviours elaborated by hypothalamic nuclei. Defensive behaviours were evaluated after the microinjection of the selective GABAA receptor antagonist bicuculline into the MH that was preceded by microinjection of either WB4101, RX821002, propranolol (α1-, α2- and ß-noradrenergic receptor selective antagonists, respectively), or physiological saline into the MH of male Wistar rats. The α1-, α2- and ß-noradrenergic receptors were found in neuronal perikarya of all MH nuclei, and the α2-noradrenergic receptor were also found on glial cells mainly situated in the ventrolateral division of the ventromedial hypothalamic nucleus. The α1- and ß-noradrenergic receptors blockade in the MH decreased defensive attention and escape reactions elicited by the intra-MH microinjections of bicuculline. These findings suggest that, despite the profuse distributions of α1-, α2- and ß-noradrenergic receptors in the MH, both α1- and ß-noradrenergic receptor- rather than α2-noradrenergic receptor-signalling in MH are critical for the neuromodulation of panic-like behaviour.

Relaxin (a regulatory-peptide) enhances cryotolerance, fertility potential and plasma reproductive hormones of Nili Ravi buffalo (Bubalus bubalis) during low breeding season.

This study investigated the beneficial effects of relaxin on cryotolerance of buffalo spermatozoa and reproductive hormones during low breeding season. Collected semen was diluted in five aliquots with relaxin addition (0.25 mg/mL, 0.50 mg/mL, 0.75 mg/mL, 1 mg/mL, and control). After gentle dilution (37°C), cooling (4°C, 2 h), equilibration (4°C, 4 h), and packaging (straws, polyvinyl French, 0.5 mL), frozen (cell freezer), and thawed (37°C, 30 s) for analysis. Blood samples were collected at different time intervals i.e., -60, -30 and 0 min (pre-dose) and 30, 60, 90, 120 and 150 min (post-dose) from a jugular vein. This study manifest that adding relaxin (1 mg/ mL) in freezing medium ameliorates sperm motility, functionality (%), and seminal plasma total antioxidant capacity (TAC, µM/L) than control during low breeding season. Furthermore, we found that relaxin supplementation at 1 mg/mL significantly improves seminal plasma ATP concentrations (nmol/million) than control, 0.25 mg/mL, and 0.50 mg/mL, and fertility (control, and 0.75 mg/mL). Further, relaxin injection significantly improves plasma T, LH and IGF-1 levels (150 and 120 min vs. -60, and - 30), and FSH, KP, and GnRH concentrations (150 min vs. -60), during low breeding season. Taken together, this study revealed that relaxin ameliorates motility, functionality, and fertility of buffalo spermatozoa. Moreover, relaxin injection (1 mg/mL) improves essential reproductive hormones levels in buffalo signifying its importance in the field of reproductive physiology. Further studies are required to determine the exact mechanism of action of relaxin in enhancing semen quality, fertility and reproductive hormones.

Formulation Development and Characterization of pH Responsive Polymeric Nano-Pharmaceuticals for Targeted Delivery of Anti-Cancer Drug (Methotrexate).

Oral administration of pH sensitive/stimuli responsive nanoparticles are gaining importance because of the limited side effects, minimum dose and controlled drug release. The objective of this study was to develop and evaluate pH sensitive polymeric nanoparticles for methotrexate with the aim to maximize the drug release at target site. In the presented study, pH sensitive polymeric nanoparticles of methotrexate were developed through modified solvent evaporation technique using polymer Eudragit S100. Different process parameters like drug to polymer ratio, speed of sonication, concentration of surfactant and time of sonication were optimized by evaluating their effects on particle size, PDI, zeta potential, entrapment/encapsulation efficiency. The developed formulations were evaluated for their size, polydispersity (PDI), zeta potential, encapsulation efficiency, XRD, scanning electron microscopy, in-vitro drug release and stability studies. Best results were obtained with poloxamer-407 and PVA and were selected as surfactants. Physicochemical characterization of the developed formulations showed that the particle size lies in the range 165.7 ± 1.85-330.4 ± 4.19, PDI 0.119 ± 0.02-0.235 ± 0.008, zeta potential -0.163 ± 0.11--5.64 ± 0.36 mV, and encapsulation efficiency more than 61%. The results of scanning electron microscopy revealed that nanoparticles have regular geometry with spherical shape. Initially the drug release occur through diffusion followed by erosion. The present studies showed that MTX-ES100 nanoparticles prepared during this study have the desired physicochemical properties, surface morphology and release characteristics used to target the desired organs.

The ameliorating effects of crocetin on frozen-thawed quality, and fertility via attenuating oxidative status of bubaline spermatozoa.

Current study was conducted to appraise the cryoprotective influence of crocetin on quality, oxidative status, and fertility potential of bubaline spermatozoa. Collected semen from four bulls was diluted in five aliquots with (10 µM, 5 µM, 2 µM, 1 µM, and control [0 µM] supplementation of crocetin). After gentle dilution (37 °C), cooling (4 °C, in 2 h), equilibration (4 °C, for 4 h) and packaging of samples was done in straws (polyvinyl French, 0.5 ml), and then frozen (programmable cell freezer). This study established that crocetin supplementation significantly (p < 0.05) improves CASA (Computer Assisted Sperm motion Analyzer) total motility (%), rapid velocity (%), average-path, and curved-line velocities (µm/sec, 10 µM vs. control), and progressive motility (%), straight-line velocity (µm/sec), total antioxidant capacity (TAC, µMol/l), ATP concentrations (nmol/million), and fertility potential (%) (10 µM vs. control, and 1 µM), and mitochondrial potential (%) of buffalo spermatozoa (5, and 10 µM vs. control). Crocetin supplementation significantly (p < 0.05) alleviates DNA fragmentation, seminal plasma ROS (104 RLU/20/25 million, RLU = Relative light unit) levels, and lipid peroxidation (LPO, µMol/ml) in buffalo spermatozoa (10 µM vs. control). In a nutshell, crocetin supplementation improves post-thaw quality by means of motility parameters, motion kinematics, TAC, and ATP concentrations, and fertility potential, and abolished DNA fragmentation parameters, seminal plasma ROS, and LPO concentrations of buffalo spermatozoa. The exact mechanism by which crocetin acts are not fully elucidated; however, it is probable to speculate that the reduction in ROS, and LPO recorded in this study may be related to scavenging ability of this antioxidant during cryopreservation.

Ventrolateral periaqueductal gray matter integrative system of defense and antinociception.

Defensive responses are neurophysiological processes crucial for survival during threatening situations. Defensive immobility is a common adaptive response, in rodents, elaborated by ventrolateral periaqueductal gray matter (vlPAG) when threat is unavoidable. It is associated with somatosensory and autonomic reactions such as alteration in the sensation of pain and rate of respiration. In this study, defensive immobility was assessed by chemical stimulation of vlPAG with different doses of NMDA (0.1, 0.3, and 0.6 nmol). After elicitation of defensive immobility, antinociceptive and respiratory response tests were also performed. Results revealed that defensive immobility was followed by a decrease in the nociceptive perception. Furthermore, the lowest dose of NMDA induced antinociceptive response without eliciting defensive immobility. During defensive immobility, respiratory responses were also disturbed. Interestingly, respiratory rate was increased and interspersed with prolonged expiratory phase of breathing. These findings suggest that vlPAG integrates three different defensive behavioral responses, contributing to the most effective defensive strategies during threatening situations.

The addition of resveratrol in tris citric acid extender ameliorates post-thaw quality parameters, antioxidant enzymes levels, and fertilizing capability of buffalo (Bubalus bubalis) bull spermatozoa.

Resveratrol is a natural grape-derived polyphenol with potent antioxidant properties that protect spermatozoa against lipid peroxidation (LPO) by eradicating free radicals. The objectives of this study were to 1) appraise the effects of resveratrol in extender on post-thaw quality parameters, antioxidant enzymes, adenosine triphosphate (ATP), DNA fragmentation, LPO and 2) fertilizing capability of buffalo bull spermatozoa. Semen was collected from four fertility proven bulls with artificial vagina thrice, evaluated initially, and diluted in five different extenders containing resveratrol (T4 = 100 µM, T3 = 50 µM, T2 = 20 µM, T1 = 10 µM), and control (no resveratrol), and evaluated after post-dilution and post-thawing stage of cryopreservation. Analysis of variance revealed that, there was no difference (P > 0.05) in any parameters due to treatments at post-dilution. However, at post-thawing, sperm progressive motility (%), plasma membrane integrity (%), mitochondrial membrane potential (%) and ATP levels (nmol/106) were found higher in semen samples cryopreserved in T3 and 4 than control. Sperm supravital plasma membrane integrity (%) and viable/acrosome integrity were found higher in semen samples cryopreserved in T4 than control and T1. Furthermore, sperm catalase (U/mL), glutathione peroxidase (µM) and superoxide dismutase (U/mL) concentrations were found significantly higher in resveratrol treated groups as compared to the control. Conversely, DNA fragmentation (%) and LPO (µM/mL) were significantly (P > 0.05) decreased in semen samples cryopreserved in T4 in comparison to the control. Fertilizing capability was found higher in semen samples cryopreserved in T4 as compared to the control (%, 77.33 vs. 57.41, P < 0.05). It is concluded that the addition of resveratrol in extender ameliorates quality parameters, antioxidant enzymes levels and fertilizing capability, and alleviate DNA fragmentation and LPO in buffalo spermatozoa during cryopreservation.

Defensive behaviors and brain regional activation changes in rats confronting a snake.

In the present study, we examined behavioral and brain regional activation changes of rats). To a nonmammalian predator, a wild rattler snake (Crotalus durissus terrificus). Accordingly, during snake threat, rat subjects showed a striking and highly significant behavioral response of freezing, stretch attend, and, especially, spatial avoidance of this threat. The brain regional activation patterns for these rats were in broad outline similar to those of rats encountering other predator threats, showing Fos activation of sites in the amygdala, hypothalamus, and periaqueductal gray matter. In the amygdala, only the lateral nucleus showed significant activation, although the medial nucleus, highly responsive to olfaction, also showed higher activation. Importantly, the hypothalamus, in particular, was somewhat different, with significant Fos increases in the anterior and central parts of the ventromedial hypothalamic nucleus (VMH), in contrast to patterns of enhanced Fos expression in the dorsomedial VMH to cat predators, and in the ventrolateral VMH to an attacking conspecific. In addition, the juxtodorsalmedial region of the lateral hypothalamus showed enhanced Fos activation, where inputs from the septo-hippocampal system may suggest the potential involvement of hippocampal boundary cells in the very strong spatial avoidance of the snake and the area it occupied. Notably, these two hypothalamic paths appear to merge into the dorsomedial part of the dorsal premammillary nucleus and dorsomedial and lateral parts of the periaqueductal gray, all of which present significant increases in Fos expression and are likely to be critical for the expression of defensive behaviors in responses to the snake threat.

Supplementation of l-tryptophan (an aromatic amino acid) in tris citric acid extender enhances post-thaw progressive motility, plasmalemma, mitochondrial membrane potential, acrosome, and DNA integrities, and in vivo fertility rate of buffalo (Bubalus bubalis) bull spermatozoa.

The aromatic amino acid l-tryptophan is an essential and versatile molecule, acts by transferring an electron to free radicals and protects the plasma membrane from injuries. The aim of the present study was to investigate the effects of l-tryptophan in extender on semen quality parameters, in vitro longevity and in vivo fertility rate of buffalo spermatozoa during cryopreservation. Two ejaculates were collected from each bull (n = 2 ejaculates and n = 4 bulls) with artificial vagina at 42 °C followed by initial evaluation for volume, motility, concentrations and were diluted in five extenders (C = lacking l-tryptophan, D1 = 25 µ M l-tryptophan, D2 = 50 µ M l-tryptophan, D3 = 75 µ M l-tryptophan, and D4 = 100 µ M l-tryptophan) respectively, and cryopreserved. The experiment was repeated four times (n = 4 replicates). At post-dilution, sperm plasma membrane integrity (PMI, %), supravital plasma membrane integrity (SVPMI, %), hypo-resistivity (HR, %) and acrosome integrity (ACR-I, %) were significantly higher (P < 0.05) in extender supplemented with D4 than control. At post-thawing, progressive motility (PM, %), PMI, SVPMI, HR, ACR-I, and DNA-I of buffalo bull spermatozoa were significantly higher in D4 than control. Sperm in vitro longevity (%) assessed in terms of PM, SVPMI, and ACR-1 were significantly higher in D4 than control. Sperm mitochondrial membrane potential (%) was higher in treated groups than the control. The in vivo fertility rate was significantly higher in D4 than control (60.17% vs. 44.17%, P < 0.05). It is concluded that the supplementation of l-tryptophan in tris citric acid extender improves semen quality parameters, in vitro longevity and in vivo fertility rate of buffalo spermatozoa during freezing and thawing process.

Stimulating effects of Quercetin (QUE) in tris citric acid extender on post thaw quality and in vivo fertility of buffalo (Bubalus bubalis) bull spermatozoa.

Aim of this study was to evaluate the stimulating effects of quercetin (QUE) on post thaw quality and in vivo fertility of buffalo (Bubalus bubalis) bull spermatozoa. QUE is a well-known flavonoid having antioxidant properties to scavenge free radicals. Semen was collected from three buffalo bull through artificial vagina (42 °C) and were evaluated initially for volume, motility, concentration, followed by dilution in five extenders (n = 5 aliquots, control, C = no QUE; treatment 1, T1 = 50 µM QUE; treatment 2, T2 = 100 µM QUE; treatment 3, T3 = 150 µM QUE and treatment 4, T4 = 200 µM QUE supplementation). The experiment was repeated thrice (n = 3 replicates). At post dilution, sperm progressive motility (PM, %) plasma membrane integrity (PMI, %), supra vital plasma membrane integrity (SVPMI, %) and acrosome integrity (ACR-1, %) of buffalo bull were significantly higher (P < 0.05) in extenders supplemented with QUE than C. At thawing, sperm PM of buffalo bull was higher in T3 and T4 than C, T1 and T2. Sperm SVPMI was significantly higher in T2, T3 and T4 than C and T1. Sperm ACR-I was higher in T3 and T4 than C, T1 and T2. Sperm DNA integrity was higher in T4 than C. QUE supplementation increased in vitro semen quality during 30 and 60 min of incubation at 37 °C than C. The in vivo fertility was higher in T3 and T4 than C (%, 61.82 vs. 65.22 vs. 46.90). It is concluded that QUE @ 150 and 200 µM improved post thaw semen quality and in vivo fertility of buffalo bull.

Metabolic Impact on the Hypothalamic Kisspeptin-Kiss1r Signaling Pathway.

A large body of data has established the hypothalamic kisspeptin (KP) and its receptor, KISS1R, as major players in the activation of the neuroendocrine reproductive axis at the time of puberty and maintenance of reproductive capacity in the adult. Due to its strategic location, this ligand-receptor pair acts as an integrator of cues from gonadal steroids as well as of circadian and seasonal variation-related information on the reproductive axis. Besides these cues, the activity of the hypothalamic KP signaling is very sensitive to the current metabolic status of the body. In conditions of energy imbalance, either positive or negative, a number of alterations in the hypothalamic KP signaling pathway have been documented in different mammalian models including nonhuman primates and human. Deficiency of metabolic fuels during fasting causes a marked reduction of Kiss1 gene transcript levels in the hypothalamus and, hence, decreases the output of KP-containing neurons. Food intake or exogenous supply of metabolic cues, such as leptin, reverses metabolic insufficiency-related changes in the hypothalamic KP signaling. Likewise, alterations in Kiss1 expression have also been reported in other situations of energy imbalance like diabetes and obesity. Information related to the body's current metabolic status reaches to KP neurons both directly as well as indirectly via a complex network of other neurons. In this review article, we have provided an updated summary of the available literature on the regulation of the hypothalamic KP-Kiss1r signaling by metabolic cues. In particular, the potential mechanisms of metabolic impact on the hypothalamic KP-Kiss1r signaling, in light of available evidence, are discussed.

Bioaccumulation of Some Heavy Metals: Analysis and Comparison of Cyprinus carpio and Labeo rohita from Sardaryab, Khyber Pakhtunkhwa.

We examined and compared heavy metals bioaccumulation in Cyprinus carpio and Labeo rohita netted from Sardaryab, a tributary of River Kabul. By using atomic absorption spectrometry we assessed different organs including livers, gills, and muscles. Metals studied were chromium, iron, zinc, lead, and copper. Livers of both species showed higher concentrations of metals while muscles showed the least amount. Chromium and iron were the highly concentrated metals in the gills and livers of both species. A quantity of 0.154 ± 0.011, 0.199 ± 0.0079, and 0.024 ± 0.008 µg/g of chromium was found in the gills, livers, and muscles of Cyprinus carpio, respectively. Similarly, the gills, liver, and muscles of Labeo rohita contained 0.133 ± 0.008, 0.165 ± 0.01, and 0.019 ± 0.006 µg/g of Cr, respectively. Iron was highest in carp in the range of 0.086 ± 0.01 in gills and 0.067 ± 0.011 µg/g in muscles, comparatively. All the studied metals were found within the US recommended daily dietary allowances (RDA) limits; hence no immediate risk in their consumption for human was found. The data showed that Cyprinus carpio being omnivorous and bottom feeder stored higher concentrations of metals as compared to Labeo rohita.

CB1 cannabinoid receptor-mediated anandamide signalling reduces the defensive behaviour evoked through GABAA receptor blockade in the dorsomedial division of the ventromedial hypothalamus.

The effects of cannabinoids in brain areas expressing cannabinoid receptors, such as hypothalamic nuclei, are not yet well known. Several studies have demonstrated the role of hypothalamic nuclei in the organisation of behavioural responses induced through innate fear and panic attacks. Panic-prone states are experimentally induced in laboratory animals through a reduction in the GABAergic activity. The aim of the present study was to examine panic-like elaborated defensive behaviour evoked by GABAA receptor blockade with bicuculline (BIC) in the dorsomedial division of the ventromedial hypothalamus (VMHdm). We also aimed to characterise the involvement of endocannabinoids and the CB1 cannabinoid receptor in the modulation of elaborated defence behavioural responses organised with the VMHdm. The guide-cannula was stereotaxicaly implanted in VMHdm and the animals were treated with anandamide (AEA) at different doses, and the effective dose was used after the pre-treatment with the CB1 receptor antagonist AM251, followed by GABAA receptor blockade in VMHdm. The results showed that the intra-hypothalamic administration of AEA at an intermediate dose (5 pmol) attenuated defence responses induced through the intra-VMHdm microinjection of bicuculline (40 ng). This effect, however, was inhibited when applied central microinjection of the CB1 receptor antagonist AM251 in the VMHdm. Moreover, AM251 potentiates de non-oriented escape induced by bicuculline, effect blocked by pre-treatment with the TRPV1 channel antagonist 6-I-CPS. These results indicate that AEA modulates the pro-aversive effects of intra-VMHdm-bicuculline treatment, recruiting CB1 cannabinoid receptors and the TRPV1 channel is involved in the AM251-related potentiation of bicuculline effects on non-oriented escape behaviour.

Connexions between the dorsomedial division of the ventromedial hypothalamus and the dorsal periaqueductal grey matter are critical in the elaboration of hypothalamically mediated panic-like behaviour.

The electrical and chemical stimulation of the dorsal periaqueductal grey matter (dPAG) elicits panic-like explosive escape behaviour. Although neurons of the ventromedial hypothalamus (VMH) seem to organise oriented escape behaviour, when stimulated with excitatory amino acids at higher doses, non-oriented/explosive escape reactions can also be displayed. The aim of this work was to examine the importance of reciprocal projections between the VMH and the dPAG for the organisation of this panic-like behaviour. The chemical stimulation of the VMH with 9nmol of N-methyl-d-aspartic acid (NMDA) elicited oriented and non-oriented escape behaviours. The pretreatment of the dPAG with a non-selective blocker of synaptic contacts, cobalt chloride (CoCl2), followed by stimulation of the dorsomedial part of the ventromedial hypothalamus (dmVMH) with 9nmol of NMDA, abolished the non-oriented/explosive escape and freezing responses elicited by the stimulation of the dmVMH. Nonetheless, the rats still showed oriented escape to the burrow. On the other hand, when the blockade of the dmVMH with CoCl2 was followed by stimulation of the dPAG with 6nmol of NMDA, no effect was observed either on the non-oriented/explosive escape or on the freezing behaviour organised by the dPAG. Furthermore, Fos protein-labelled neurons were observed in the dPAG after the stimulation of the dmVMH with 9nmol of NMDA. Additionally, when the anterograde neurotracer biotinylated dextran amine (BDA) was deposited in the dmVMH subsequent stimulation of the dmVMH produced BDA-labelled neural fibres with terminal boutons surrounding Fos-labelled neurons in the dPAG, suggesting synaptic contacts between dmVMH and dPAG neurons for eliciting panic-like behavioural responses. The current data suggest that the dPAG is the key structure that organises non-oriented/explosive escape reactions associated with panic attack-like behaviours.

The µ1-opioid receptor and 5-HT2A- and 5HT2C-serotonergic receptors of the locus coeruleus are critical in elaborating hypoalgesia induced by tonic and tonic-clonic seizures.

It has been proposed that the post-ictal state is associated with the expression of hypoalgesia. It is clear that the projections among the periaqueductal gray matter (PAG), dorsal raphe nucleus (DRN) and locus coeruleus (LC) play a role in pain management. These mesencephalic structures have direct reciprocal opioid and monoaminergic projections to the LC that can possibly modulate post-ictal hypoalgesia. The goal of this study was to examine if LC-opioid and serotonergic/noradrenergic mechanisms signal the post-ictal hypoalgesic responses to tonic-clonic seizures produced by intraperitoneal administration of pentylenetetrazole (PTZ at 64mg/kg), causing an ionophore γ-aminobutyric acid (GABA)-mediated Cl- influx antagonism. The rodents' nociceptive threshold was measured by the tail-flick test. Intra-LC cobalt chloride (1.0nM/0.2µL) microinjections produced intermittent local synaptic inhibition and were able to reduce post-ictal hypoalgesia. Central administration of naltrexone (a non-selective antagonist for opioid receptors), naloxonazine (a selective antagonist for µ1-opioid-receptors), methysergide (a non-selective antagonist for serotonergic receptors) or ketanserin (an antagonist for both α1-noradrenergic and 5-Hydroxytryptamine(HT)2A/2C receptors) at 5.0µg/0.2µL, R-96544 (a 5-HT2A receptor selective antagonist) at 10nM/0.2µL, or RS-102221 (a 5-HT2C receptor selective antagonist) at 0.15µg/0.2µL into the LC also decreased post-ictal hypoalgesia. The data presented here suggest that the post-ictal antinociception mechanism involves the µ1-opiod, 5-HT2A- and 5-HT2C-serotonergic, and α1-noradrenergic receptors in the LC.

Simultaneous determination of moxifloxacin and ofloxacin in physiological fluids using high performance liquid chromatography with ultraviolet detection.

A novel, sensitive and validated RP-HPLC-UV method was developed for simultaneous determination of moxifloxacin and ofloxacin using timolol maleate as internal standard in physiological fluids. Different experimental parameters were optimized and validated according to international guidelines. Complete separation of the analytes was achieved with Kromasil 100-5C18 analytical column (250mm×4.6mm×5µm), methanol and 0.05% trifloroacetic acid (TFA) (38:62v/v) were used as mobile phase, pumped at flow rate of 1.1ml/min in isocratic phase, column oven temperature maintained at 45°C and detection wavelength of 290nm. Protein precipitation method was applied to extract the drugs from human plasma and bovine aqueous humor samples using methanol as precipitating solvent. This method is linear in concentration range of 0.018-100µg/ml for moxifloxacin and 0.014-20µg/ml for ofloxacin. The recoveries of the method were 97.52 and 97.39% in human plasma for MX and OFN respectively, while in aqueous humor 94.48% for MX. The LOD values in plasma were found to be 10.0 and 8.00ng/ml for MX and OFN respectively, while their respective LOQ values were 18.0 and 14ng/ml. In aqueous humor the LOD and LOQ for MX were 16.0 and 24ng/ml respectively. In future, this method will be used to study the pharmacokinetic profile of moxifloxacin and ofloxacin in biological fluids and pharmaceutical products.

Neuroethological validation of an experimental apparatus to evaluate oriented and non-oriented escape behaviours: Comparison between the polygonal arena with a burrow and the circular enclosure of an open-field test.

Inhibition of GABAergic neural inputs to dorsal columns of the periaqueductal grey matter (dPAG), posterior (PH) and dorsomedial (DMH) hypothalamic nuclei elicits distinct types of escape behavioural reactions. To differentiate between the variety and intensity of panic-related behaviours, the pattern of defensive behaviours evoked by blockade of GABAA receptors in the DMH, PH and dPAG were compared in a circular open-field test and in a recently designed polygonal arena. In the circular open-field, the defensive behaviours induced by microinjection of bicuculline into DMH and PH were characterised by defensive alertness behaviour and vertical jumps preceded by rearing exploratory behaviour. On the other hand, explosive escape responses interspersed with horizontal jumps and freezing were observed after the blockade of GABAA receptors on dPAG neurons. In the polygonal arena apparatus, the escape response produced by GABAergic inhibition of DMH and PH neurons was directed towards the burrow. In contrast, the blockade of GABAA receptors in dPAG evoked non-oriented escape behaviour characterised by vigorous running and horizontal jumps in the arena. Our findings support the hypothesis that the hypothalamic nuclei organise oriented escape behavioural responses whereas non-oriented escape is elaborated by dPAG neurons. Additionally, the polygonal arena with a burrow made it easy to discriminate and characterise these two different patterns of escape behavioural responses. In this sense, the polygonal arena with a burrow can be considered a good methodological tool to discriminate between these two different patterns of escape behavioural responses and is very useful as a new experimental animal model of panic attacks.

Relevance of dorsomedial hypothalamus, dorsomedial division of the ventromedial hypothalamus and the dorsal periaqueductal gray matter in the organization of freezing or oriented and non-oriented escape emotional behaviors.

Electrical stimulation of the periaqueductal gray matter and ventromedial hypothalamus in humans showed the involvement of both these structures in panic attacks. The aim of this work was to make clear the role of dorsal periaqueductal gray (dPAG) matter, dorsomedial hypothalamus (DMH) and the dorsomedial part of the ventromedial hypothalamus (dmVMH) in panic attack-like behaviors. DMH, dmVMH and dPAG of Wistar rats were treated with N-methyl- d-aspartic acid (NMDA) at different doses. The rodents were then kept in a polygonal arena with a burrow to record panic attack-like responses and oriented defensive behaviors. In dmVMH, 6nmol of NMDA elicited alertness, freezing and oriented escape. The same set of behaviors was elicited by DMH neurons when stimulated by 9nmol of NMDA. Treatment of dmVMH with 9nmol of NMDA elicited typical explosive behaviors followed by freezing and oriented behaviors. The stimulation of the dPAG with NMDA at different doses provoked alertness and freezing (1nmol) or alertness, freezing, tail twitching, explosive behavior and oriented escape (3nmol), and explosive behavior followed by long-lasting freezing (6nmol). These data suggest that mainly dPAG plays a role in panic attack-like behaviors that resemble panic syndrome in humans. However, hypothalamic nuclei like dmVMH that mainly elicits oriented escape, can also produce explosive reaction when stimulated with 9nmol NMDA, whereas, DMH plays a role in coordinating defensive behaviors.