Histamine excites rat lateral vestibular nuclear neurons through activation of post-synaptic H2 receptors

Through whole-cell patch recordings in brainstem slices, the effects of histamine on neuronal activity of the lateral vestibular nucleus (LVN) were investigated. Bath application of histamine elicited a concentration-dependent excitation of both spontaneous firing (n = 19) and silent (n = 7) LVN neurons. Moreover, histamine induced a stable inward current in the LVN neurons (n = 5) and the histamine-induced depolarization of membrane potential persisted in the presence of tetrodotoxin (n = 4), indicating a direct post-synaptic effect of the histamine on the LVN neurons. Selective histamine H2 receptor antagonist ranitidine effectively blocked the histamine-evoked excitatory responses on the LVN neurons (n = 4), but selective histamine H1 receptor antagonist triprolidine did not (n = 4). In addition, selective histamine H2 receptor agonist dimaprit (n = 3) rather than 2-pyridylethylamine (n = 4), a selective histamine H1 receptor agonist, mimicked the excitatory action of histamine on LVN neurons. The results demonstrate that histamine excites the LVN neurons via post-synaptic histamine H2 receptors and suggest that the central histaminergic projection arising from the hypothalamus may modulate LVN neurons activity and actively influence the vestibular reflexes and functions.     

Dependence of the anterior olfactory area self-stimulation upon the lateral hypothalamic area

The functional relation between the anterior olfactory area (AO) and the lateral hypothalamic area (LH) was examined in a self-stimulation situation. Bar-pressing responses for AO sitmulation were suppressed by unilateral injection of procaine, and enhanced by glutamate, into LH. Neither procaine nor glutamate injected into AO had any influence upon LH self-stimulation. It is unlikely that the procaine effect was due to motor disturbance because similar injection of procaine into LH did not disturb the performance of a one-way avoidance task. It appears that the rewarding effect of AO stimulation is dependent upon the excitation of the more caudal structures including LH.     

Development of brain stimulation reward in the medial prefrontal cortex: Facilitation by prior electrical stimulation of the sulcal prefrontal cortex

Electrical stimulation of the medial prefrontal cortex (MC) in rats delivered daily for seven days causes a marked improvement in the rate of acquisition of a self-stimulation response. In the present experiment, we looked at whether we could get the same facilitatory effect on self-stimulation of the MC by delivering pre-training stimulation to other points in the brain anatomically related to the MC. Electrical stimulation of the lateral hypothalamus was without effect. However, electrical stimulation of the sulcal prefrontal cortex (SC) either contralateral or ipsilateral to the MC electrode did facilitate acquisition of self-stimulation of the MC. Thus the SC and MC would appear to be part of the same substrate controlling the development of positive reinforcement in the MC.     

Dopamine and serotonin: influences on male sexual behavior

Steroid hormones regulate sexual behavior primarily by slow, genomically mediated effects. These effects are realized, in part, by enhancing the processing of relevant sensory stimuli, altering the synthesis, release, and/or receptors for neurotransmitters in integrative areas, and increasing the responsiveness of appropriate motor outputs. Dopamine has facilitative effects on sexual motivation, copulatory proficiency, and genital reflexes. Dopamine in the nigrostriatal tract influences motor activity; in the mesolimbic tract it activates numerous motivated behaviors, including copulation; in the medial preoptic area (MPOA) it controls genital reflexes, copulatory patterns, and specifically sexual motivation. Testosterone increases nitric oxide synthase in the MPOA; nitric oxide increases basal and female-stimulated dopamine release, which in turn facilitates copulation and genital reflexes. Serotonin (5-HT) is primarily inhibitory, although stimulation of 5-HT(2C) receptors increases erections and inhibits ejaculation, whereas stimulation of 5-HT(1A) receptors has the opposite effects: facilitation of ejaculation and, in some circumstances, inhibition of erection. 5-HT is released in the anterior lateral hypothalamus at the time of ejaculation. Microinjections of selective serotonin reuptake inhibitors there delay the onset of copulation and delay ejaculation after copulation begins. One means for this inhibition is a decrease in dopamine release in the mesolimbic tract.     

Phasic stimulation of the locus coeruleus: Effects on activity in the lateral geniculate nucleus

Neurons in the locus coeruleus (LC) encode information related to behavioral state in a tonic pattern of firing and information related to the occurrence of a sensory stimulus in a phasic pattern of firing. The effects of phasic stimulation of the LC (6 pulses at 30 Hz), designed to approximate its physiological activation by sensory stimuli, were studied in the lateral geniculate nucleus (LGN) of anesthetized rats. Phasic stimulation of the LC significantly increased neuronal firing in the LGN with a mean latency 320 ms from onset of stimulation. Receiver operating characteristic analyses on a trial-by-trial basis showed that phasic LC stimulation can result in a highly discriminable signal in the LGN. This increased neuronal firing rate in the LGN was specific for the site of stimulation and was reduced by the norepinephrine synthesis inhibitor αmethyl-p-tyrosine and by intravenous WB-4101 (α₁-receptor antagonist). Neurons in the LGN have a singlespike firing mode when sensory information is faithfully relayed from retina to cortex and a burst-firing mode when the transfer of this information is degraded. Phasic LC stimulation reduced burst firing (2–5 ms interspike intervals, ISIs) at low frequencies ( ≤4 Hz) in the LGN, and for some neurons there was an absolute decrease in burst-like ISIs after LC stimulation, despite an increase in mean firing rate.     

Lateral actions at the inner plexiform layer of the carp retina: effects of turning windmill pattern stimulus

Lateral action from amacrine to ganglion cells was studied in the isolated carp retina by using a truncated windmill pattern (TWP). About 25% of ganglion cells of both "on" and "off" center types were suppressed or enhanced in firing activity in response to TWP turning. The suppressed cells were more sensitive to slow turning velocities of TWP than the enhanced cells. In the "on-off" type amacrine cells, a steady depolarizing or hyperpolarizing component (less than several mV) was maintained by stationary TWP, while the cells were exclusively depolarized by turning TWP at a wide range of velocities. These results suggest that individual responses of ganglion cells induced by both stationary and turning TWP are depending on a balance between two factors: the polarizing direction of steady components of the "on-off" amacrine cells and the polarizing direction of ganglion cells synaptically produced by the amacrine cells.     

旋髂深动脉及其临近结构的观测

目的：研究旋髂深动脉与临近结构的位置关系,为临床应用提供解剖学依据。方法：应用成年尸体20具（40侧,男尸12具,女尸8具）,观察旋髂深动脉,髂腹下神经,髂腹股沟神经,股外侧皮神经及它们之间的位置关系,结果：旋髂深动脉与神经之间有密切的毗邻关系,结论：临床上在作髂骨瓣移植分离切断旋髂深动脉及其分支时,应注意保护有关的神经。     

The Patient-Rated Tennis Elbow Evaluation Questionnaire was successfully translated to Persian

IntroductionThe Patient-Rated Tennis Elbow Evaluation (PRTEE) is designed to evaluate pain and disability in subjects with lateral elbow tendinopathy. This questionnaire is available in Swedish, Italian, and some other languages. A Persian language version of the questionnaire is needed for both research and clinical purposes.Purpose of the StudyThe purpose of this study was to translate and cross-culturally adapt the PRTEE questionnaire into the Persian language and to determine its validity and reliability.MethodsThe PRTEE was translated and culturally adapted from English into Persian (PRTEE-P) according to the established guidelines. The PRTEE-P was completed by 68 Iranian subjects (44 women, 24 men) diagnosed with chronic lateral elbow tendinopathy. To assess test-retest reliability, all subjects filled out the PRTEE-P on a second admission within one week. The intraclass correlation coefficient (ICC) and Cronbach's alpha were measured to report reliability. The validity was determined by correlating the PRTEE-P questionnaire with the Persian version of the Disabilities of the Arm, Shoulder, and Hand questionnaire.ResultsThe Persian version of the PRTEE showed a high internal consistency with a Cronbach's alpha of 0.99, demonstrating good test-retest reliability (ICC = 0.99). It was well correlated with Disabilities of the Arm, Shoulder, and Hand (r = 0.80).ConclusionThe PRTEE-P is a reliable and valid tool designed for measuring pain and disability in subjects with lateral elbow tendinopathy.     

Role of strengthening during nonoperative treatment of lateral epicondyle tendinopathy

IntroductionLateral epicondyle tendinopathy (LET) is the most common cause of lateral elbow pain. The literature on rehabilitation of the condition encompasses a plethora of interventions with most current evidence indicating that stretches and some form of strengthening are vital components. However, patient outcomes are infrequently reported further than 12 weeks from the start of therapy and it is unclear which components of a home exercise program are necessary to alleviate symptoms up to one year from the initiation of a therapy program.Purpose of the StudyThe purpose of the study is to determine if a therapy program with 4 to 6 visits spaced out over 12 weeks focusing on self-management and strengthening is more effective in reducing pain and improving function long term than the same program without strengthening, for individuals with LET.Study DesignThis is a randomized controlled trial.MethodsNinety-four patients were randomly allocated into two groups: both groups received the interventions of education in pertinent pathoanatomy, stretching, pain management through rest and icing, and activity modification. Group 1 (n = 38) was also provided with a strengthening component to the home exercise program, whereas group 2 did not (n = 21). Our primary outcome measure was pain at rest and pain with activity; our secondary measure was the level of functional impairment as measured by the quick disabilities of arm shoulder and hand. Outcome measurements were assessed at baseline, 6, 12, 24, and 52 weeks after initiation of therapy.ResultsBoth groups demonstrated statistically significant improvement with a moderate to large effect size in pain and function scores when compared with previous time point at 6, 12, and 24 weeks. Pain continued to decrease for both groups from 24 weeks to 52 weeks, but interestingly, there was a significant increase with moderate effect size in the quick disabilities of arm shoulder and hand score at 52 weeks when compared with week 24. No statistically significant difference was found between the two groups at any time point up to 52 weeks from the start of therapy.ConclusionsThis study demonstrates that a therapy program consisting of a low number of visits spaced out over 12 weeks based on education, stretches, activity modification, and pain management techniques is effective at reducing pain and increasing function in patients with LET. The addition of strengthening to this program did not improve outcomes. The therapy approach used in this study is consistent with the International Classification of Function guidelines and focuses on engaging patients in self-management of the condition through patient education and self-empowerment.