Immunohistochemical colocalization of TREK-1, TREK-2 and TRAAK with TRP channels in the trigeminal ganglion cells

TREK belongs to a subfamily of tandem pore domain K⁺ channels, and consists of three subunits, TREK-1, TREK-2 and TRAAK. We examined the distribution of TREK-1, TREK-2 and TRAAK immunoreactive neurons in rat trigeminal sensory neurons. In the trigeminal ganglia, 31%, 43% and 60% of neurons were immunoreactive for TREK-1, TREK-2 and TRAAK, respectively. Mean sizes of TREK-1, TREK-2 and TRAAK immunoreactive trigeminal ganglion neurons were 447 ± 185, 445 ± 23 and 492 ± 12 mm², respectively. Furthermore, TREK channels were colocalized with cationic TRP channels, TRPV1, TRPV2 and TRPM8. TREK-1 immunoreactive neurons were colocalized with TRPV1 (57%), TRPV2 (11%) and TRPM8 (33%). TREK-2-immunoreactive neurons were colocalized with TRPV1 (33%), TRPV2 (9%) and TRPM8 (19%). TRAAK immunoreactive neurons were colocalized with TRPV1 (47%), TRPV2 (10%) and TRPM8 (22%). The present results revealed that TREK-1, TREK-2 and TRAAK channels colocalized with thermosensitive TRP channels in some small trigeminal ganglion neurons.     

面向康复师进行感觉统合理论授课的实践

面向实习进修和本院在职康复师进行感觉统合理论教学，是丰富康复师理论知识、提高儿童康复技能的有效方法。文章从教学设计、教学准备和教学实施方面入手，总结了讲授Jean Ayers博士创立的感觉统合理论的经验和体会。     

Effect of spaceflight on thresholds of perception of angular and linear motion

Summary Psychophysical studies of vestibular function have been carried out in order to study adaptation within the vestibular sensory system to the weightless environment of orbital spaceflight. No significant change in the threshold of detection of whole-body angular acceleration was found, either during flight or post-flight. Experiments involving the perception of whole-body linear acceleration have yielded somewhat inconsistent results, although the weight of evidence points to an elevation and increased variability of threshold in the first few days following spaceflight. Although a change in the excitability of the saccular and macular otoliths in microgravity cannot be excluded, it is more probable that this decreased sensitivity is a manifestation of a central adaptive mechanism, in which the weighting of gravi-receptor information is reduced. Enhancement of the ability to detect linear acceleration stimuli, exhibited by some astronauts in microgravity, may be a manifestation of heightened utilization of cutaneous rather than otolithic cues.Part of the Round Table Conference presented at the Collegium ORLAS, Munich, Federal Republic of Germany, 7–10 September 1986     

Ginseng and ginsenoside Rg3, a newly identified active ingredient of ginseng, modulate Ca2+ channel currents in rat sensory neurons

There is increasing evidence that ginseng influences pain modulation. In spite of extensive behavior studies, the detailed mechanism of ginseng actions at the cellular level and the identity of the active substance have not been elucidated yet. Whole-cell patch-clamp recordings were used to examine the modulation of high-voltage-activated Ca2+ channel currents by ginseng total saponins and its various individual ginsenosides in rat dorsal root ganglion neurons. Application of ginseng total saponins suppressed Ca2+ channel currents in a dose-dependent manner. Occlusion experiments using selective blockers revealed that ginseng total saponins could modulate L-, N-, and P-type currents. The co-application of ginseng total saponins and the gamma-opioid receptor agonist, D-Ala(2), N-MePhe(4), Gly(5)-ol-enkephalin (DAMGO), produced non-additive effects in most cells tested and each effect was significantly relieved by a depolarizing prepulse. Overnight treatment of cells with pertussis toxin profoundly reduced the inhibition. Furthermore, we now report that ginsenoside Rg3, among the major fractions of ginseng saponins, is a newly identified active component for the inhibition. These results suggest that the modulation of Ca2+ channels by ginseng total saponins, in particular by ginsenoside Rg3, could be part of the pharmacological basis of ginseng-mediated antinociception.     

Cannabinoids inhibit pre- and postjunctionally sympathetic neurotransmission in rat mesenteric arteries

The effects of cannabinoids on sympathetic neurotransmission in the rat isolated perfused mesenteric arterial bed, were investigated. Electrically evoked sympathetic neurogenic vasocontraction was inhibited by the cannabinoid receptor agonists 11-hydroxy-dimethylheptyl-Delta(8)-tetrahydrocannabinol (HU210), (-)-cis-3-[2-hydroxy-4-(1,1-dimethylheptyl)phenyl]trans-4-(3-hydroxypropyl)-cyclohexanol (CP55,940) and methanandamide, and by (+)-11-hydroxy-Delta(8)-tetrahydrocannabinol (HU211), a (+)-stereoisomer of HU210. The inhibition was unaffected by cannabinoid CB(1) and CB(2) receptor antagonists. Electrically evoked release of endogenous noradrenaline from sympathetic nerves was inhibited by HU210, but not by HU211. Inhibition was blocked by a cannabinoid CB(1), but not a CB(2), receptor antagonist. HU210 attenuated contractions to noradrenaline, and all of the cannabinoids blocked contractions to KCl. Capsaicin pre-treatment had no significant effect on HU210- and CP55,940-mediated inhibition of sympathetic neurogenic contraction, but partly blocked inhibition mediated by methanandamide. These data show that cannabinoids can inhibit, by distinct pre- and postjunctional actions, sympathetic neurotransmission in the rat mesenteric arterial bed. The pre-junctional action is mediated by a cannabinoid CB(1)-like receptor, but the postjunctional action does not appear to involve either cannabinoid CB(1) or CB(2) receptors.     

Dopamine inhibits ATP-induced responses in the cat petrosal ganglion in vitro

The petrosal ganglion (PG) provides sensory innervation to the carotid sinus and carotid body through the carotid (sinus) nerve (CN). Application of either acetylcholine (ACh) or adenosine 5'-triphosphate (ATP) to the PG superfused in vitro activates CN fibers. Dopamine (DA) modulates the effects of ACh. We have previously shown that DA when applied to the PG modulates the effects of ACh on carotid sinus nerve fibers. We currently report the effects of DA on the ATP-induced responses in the isolated PG in vitro. While DA had no effect on the basal activity recorded from the CN, it reduced ATP-induced responses in a dose-dependent manner, when preceding ATP applications by 30 s. Our results suggest that DA-a transmitter present in a group of PG neurons and in carotid body cells-may act as an inhibitory modulator of ATP-evoked responses in PG neurons.     

Trans-neuronal regulation of cortical apoptosis in the adult rat olfactory system

Previous work has identified a population of neurons within the anterior piriform cortex that undergo rapid apoptosis following de-afferentation by olfactory bulbectomy in adult rats. The specific initiation signal for apoptosis in this paradigm is unknown, but may include an activity-dependent trans-neuronal cascade. The present report examined the effect of adult-onset unilateral naris occlusion, which reduces olfactory bulb afferent excitation of piriform cortex, on apoptosis (terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling [TUNEL]) in the rat anterior piriform cortex. Adult Long-Evans hooded rats received unilateral naris occlusion or a control manipulation and were sacrificed after 1, 5, 7, 10 or 20 days later. For comparison, a second group of rats received a unilateral bulbectomy and were sacrificed 24 h later. Counts of TUNEL-stained cell profiles were performed for layers I/II and layer III of the anterior piriform cortex ipsilateral and contralateral to the manipulation. The results confirmed that unilateral bulbectomy produced a dramatic increase in TUNEL labeling in layers I/II of the ipsilateral piriform cortex 24 h after bulbectomy. Unilateral naris closure also produced enhanced TUNEL labeling, although the magnitude of the effect was less than that produced by bulbectomy, and enhanced TUNEL labeling was apparent both ipsilateral and contralateral to the sealed naris compared to controls. Deprivation-induced TUNEL labeling was detectable by 24 h post-closure, peaked at 5 days and was no different from controls by 20 days post-closure. Neither bulbectomy nor naris closure affected TUNEL labeling in layer III. Together, these results suggest that there is a population of superficial cells in piriform cortex whose survival is tightly regulated by sensory input.     

感觉统合失调儿童的行为及家庭环境因素探讨

目的:探讨感觉统合失调(SID)儿童行为及家庭环境特征。方法:采用Achenbach儿童行为量表(CBCL)、家庭环境量表(FES-CV)分别对63例感觉统合失调男童及38例正常男童进行评定。结果:SID男童在CBCL量表的交往不良、体诉、社交退缩、多动等因子分均显著高于对照组(P<0. 01);在FES-CV量表中的家庭亲密度、情感表达、独立性、组织性和娱乐性得分均低于对照组(P<0 .01),而在家庭的矛盾性得分显著高于对照组(P<0 .01)。结论:感觉统合失调儿童存在较多的行为问题和不良的家庭环境因素。     

Ultrastructural analysis of neurosecretory cells in the antennae of the mosquito, Culex salinarius (Diptera: Culicidae)

An antiserum raised against the peptide, culetachykinin II, immunocytochemically detected a group of neurosecretory cells in the first flagellar segment of the antennae of both males and females of the mosquito, Culex salinarius. This is the first insect species in which neurosecretory cells have been found in the antennae. The ultrastructure of these antennal neurosecretory cells (ANC) is described, as well as their relationship to other neurons in the antennae and antennal lobe of the mosquito. These tachykinin-reactive cells contain relatively small (140–220 nm) elementary neurosecretory granules. Not only do the ANC have axons that terminate on specific glomeruli of the deutocerebrum, but these neurons also have collaterals that form neurohemal terminals in the receptor lymph channels of the dendrites of the sensory neurons. Thus, the ANC not only influence higher centers of the brain that interpret signals from the antennal sensillae, but also modulate the response of the sensory receptors. To our knowledge, this is the first report of neurosecretory cells directly affecting the signal reception of sensory neurons.