Substance P excites GABAergic neurons in the mouse central amygdala through neurokinin 1 receptor activation.

Substance P (SP) is implicated in stress regulation and affective and anxiety-related behavior. Particularly high expression has been found in the main output region of the amygdala complex, the central amygdala (CE). Here we investigated the cellular mechanisms of SP in CE in vitro, taking advantage of glutamic acid decarboxylase-green fluorescent protein (GAD67-GFP) knockin mice that yield a reliable labeling of GABAergic neurons, which comprise 95% of the neuronal population in the lateral section of CE (CEl). In GFP-positive neurons within CEl, SP caused a membrane depolarization and increase in input resistance, associated with an increase in action potential firing frequency. Under voltage-clamp conditions, the SP-specific membrane current reversed at -101.5 ± 2.8 mV and displayed inwardly rectifying properties indicative of a membrane K(+) conductance. Moreover, SP responses were blocked by the neurokinin type 1 receptor (NK1R) antagonist L-822429 and mimicked by the NK1R agonist [Sar(9),Met(O2)(11)]-SP. Immunofluorescence staining confirmed localization of NK1R in GFP-positive neurons in CEl, predominantly in PKCδ-negative neurons (80%) and in few PKCδ-positive neurons (17%). Differences in SP responses were not observed between the major types of CEl neurons (late firing, regular spiking, low-threshold bursting). In addition, SP increased the frequency and amplitude of GABAergic synaptic events in CEl neurons depending on upstream spike activity. These data indicate a NK1R-mediated increase in excitability and GABAergic activity in CEl neurons, which seems to mostly involve the PKCδ-negative subpopulation. This influence can be assumed to increase reciprocal interactions between CElon and CEloff pathways, thereby boosting the medial CE (CEm) output pathway and contributing to the anxiogenic-like action of SP in the amygdala.

Neurosteroids increase tonic GABAergic inhibition in the lateral section of the central amygdala in mice.

Neurosteroids are formed de novo in the brain and can modulate both inhibitory and excitatory neurotransmission. Recent evidence suggests that the anxiolytic effects of neurosteroids are mediated by the amygdala, a key structure for emotional and cognitive behaviors. Tonic inhibitory signaling via extrasynaptic type A γ-aminobutyric acid receptors (GABA(A)Rs) is known to be crucially involved in regulating network activity in various brain regions including subdivisions of the amygdala. Here we provide evidence for the existence of tonic GABAergic inhibition generated by the activation of δ-subunit-containing GABA(A)Rs in neurons of the lateral section of the mouse central amygdala (CeAl). Furthermore, we show that neurosteroids play an important role in the modulation of tonic GABAergic inhibition in the CeAl. Taken together, these findings provide new mechanistic insights into the effects of pharmacologically relevant neurosteroids in the amygdala and might be extrapolated to the regulation of anxiety.

Activation of neuropeptide S-expressing neurons in the locus coeruleus by corticotropin-releasing factor.

A recently discovered neurotransmitter system, consisting of neuropeptide S (NPS), NPS receptor, and NPS-expressing neurons in the brain stem, has received considerable interest due to its modulating influence on arousal, anxiety and stress responsiveness. Comparatively little is known about the properties of NPS-expressing neurons. Therefore in the present study, a transgenic mouse line expressing enhanced green fluorescent protein (EGFP) in NPS neurons was used to characterize the cellular and functional properties of NPS-expressing neurons located close to the locus coeruleus. Particular emphasis was on the influence of corticotropin-releasing factor (CRF), given previous evidence of stress-related activation of the NPS system. Upon acute immobilization stress, an increase in c-fos expression was detected immunocytochemically in brain stem NPS-EGFP neurons that also expressed the CRF receptor 1 (CRF1). NPS-EGFP neurons were readily identified in acute slice preparations and responded to CRF application with a membrane depolarization capable of triggering action potentials. CRF-induced responses displayed pharmacological properties indicative of CRF1 that were mediated by both a reduction in membrane potassium conductance and an increase in a non-specific cation conductance different from the hyperpolarization-activated cation conductance Ih, and involved protein kinase A signalling. In conclusion, stress exposure results in activation of brain stem NPS-expressing neurons, involving a CRF1-mediated membrane depolarization via at least two ionic mechanisms. These data provide evidence for a direct interaction between the CRF and the NPS system and thereby extend previous observations of NPS-modulated stress responsiveness towards a mechanistic level.

[ADP-ribose and cADP-ribose--endogenous regulators of cellular ionic balance. Cardiotropic effects of ADP-ribose].

Functions and possible mechanisms of action of adenosine diphosphate ribose (ADP-ribose) and its cyclic analogue--cycle-ADP-ribose (cADP-ribose)-- substances pretend to role of novel second messengers are reviewed. Possible mechanisms of ADP-ribose and cADP-ribose synthesis regulation and metabolism are analyzed. Prospective mechanisms of ADP-ribose and cADP-ribose transportation into the cell are described. ADP-ribose and cADP-ribose are considered as endogenous regulators of ionic balance (in particular regulators of calcium balance) in different tissues. Effects of ADP-ribose on isolated heart of frog and warm-blooded animal (rat), as well as on rat heart in vivo are discussed. The role of ionic channels and receptors, gated by ADP- and cADP-ribose in regulation of cardiomyocyte ionic balance in normal and pathological condition are analyzed. The possible role of purine receptors in ADP-ribose and cADP-ribose effects on heart are discussed.

Location and intensity of IL-8 and TGF-beta2 mRNA production in the fimbrial compartment of fallopian tubes and IL-10 in the endometrium in patients with pyoinflammatory adnexal diseases.

The location and level of IL-8 and TGF-beta2 expression in the fimbrial compartment of fallopian tubes and IL-10 expression in the endometrium of women with pyoinflammatory adnexal diseases were studied by in situ hybridization. These diseases are associated with considerable changes in the levels of local production of these cytokines. Inflammatory infiltration and epithelial cells were most active producers of IL-9 and TGF-beta2 in the fimbrial compartment of fallopian tubes, while in the endometrium IL-10 gene was expressed at a high level primarily in the glandular epithelial cells.

Apoptosis in fimbriae of fallopian tubes and endometrium in pyoinflammatory adnexal diseases.

In patients with pyoinflammatory adnexal diseases moderate or intense DNA degradation was observed in the majority of epithelial, stromal, and inflammatory infiltration cell in inflammatory foci in the fimbrial compartment of fallopian tubes without signs of tissue destruction. Expression of TNFR1 gene increased 2.7-fold and expression of Fas gene decreased 3.1-fold compared to intact endosalpinx, which indicates induction of apoptosis triggered by tumor necrosis factor-alpha and inhibition of the Fas-dependent pathway. No signs of apoptosis were detected in the endometrium. Generalized apoptosis in the fimbrial compartment of the tubes can be a mechanism limiting the inflammatory process.

Local expression of cytokine genes in uterine adnexa and endometrium of women with pyoinflammatory adnexal diseases.

Changes in the local expression of IL-1beta, IL-2, IL-4, IL-6, IL-8, IL-10, IL-12, IL-15, IL-18, TNF-alpha, IFN-gamma- and TGF-beta(2) genes in the uterine adnexa and endometrium were studied in women with pyoinflammatory adnexal diseases. Examination of tissue specimens from the uterine adnexa involved in inflammation revealed a direct correlation in the levels of mRNA production between IL-6 and IL-10 (r=0.93, p<0.1), IL-6 and IL-4 (r=0.96, p<0.01), IL-10 and IL-4 (r=0.91, p<0.01), IL-12 and IFN-gamma (r=0.98, p<0.01). Expression of IL-4 gene increased 5.1-fold (p=0.001), IL-6 2-fold (p=0.007), IL-8 90.2-fold (p=0.009), IL-10 2.9-fold (p=0.008), IL-12 2.3-fold (p=0.3), and TGF-beta(2) gene 10.3-fold (p=0.1). In the endometrium of women with pyoinflammatory adnexal diseases only IL-10 gene expression increased (15.6-fold, p=0.007).

Expression of cytokine genes in blood mononuclear cells in women with pyoinflammatory diseases of adnexa uteri.

Production of interleukin, interferon-gamma, and transforming growth beta(2)-factor mRNA in peripheral blood mononuclear cells was studied in women with pyoinflammatory diseases of adnexa uteri. Predominant expression of Th1 proinflammatory cytokine genes in patients was demonstrated. Production of interleukins 4 and 8 mRNA decreased 200- and 60-fold, respectively, in comparison with that in healthy women. One month and a half after extirpation of fallopian tubes the cytokine production in blood mononuclear cells shifted towards antiinflammatory cytokines, expression of interleukin-8 gene returned to normal, and expression of interleukin-4 gene increased.

[The action of ADP ribose on the mechanical and bioelectrical activity of the frog heart]. / Deistvie ADF-ribozy na mekhanicheskuiu i bioélektricheskuiu aktivnost' serdtsa liagushki.

In the frog isolated heart, cyclic perfusion of ADP-ribose induced a dose-dependent decrease in the heart rate and the contraction force, a decrease in the AP duration as well as in the rate of rise in the sinus node. It also shortened the atrial AP and exerted no significant effect upon multicellular ventricular preparations. In conditions of systemic administration in unanesthetised frogs, the ADP-ribose induced a reversible increase in the heart rate due, probably, to a sympathetic effect.

[The determination of sialidase activity in the blood serum and saliva]. / Opredelenie aktivnosti sialidazy v syvorotke krovi i sliune.

A method for sialidase (neuraminidase; EC 3.2.1.18) measurements in the blood serum and saliva has been developed. The activity of this enzyme in the blood serum manifests in repeated intensive stressogenic exposures, malignant tumors and acute respiratory diseases. Salivary sialidase activity is elevated in the patients with multiple dental caries.

[Determination of free and bound forms of sialic acids in biologic objects]. / Opredelenie svobodnoi i sviazannykh form sialovykh kislot v biologicheskikh ob"ektakh.

A method for simultaneous measurements of free, oligomer-bound and protein-bound sialic acids in the blood serum, saliva, and tissue homogenates is offered. The results of these parameters measurements after stressogenic exposures and in some diseases are presented.