The occurrence of stress and anxiety disorders has been closely associated with alterations of the amygdala GABAergic system. In these disorders, dysregulation of the serotonergic system, a very important modulator of the amygdala GABAergic system, is also well recognized. The present study, utilizing a learned helplessness stress rat model, was designed to determine whether stress is capable of altering serotonergic modulation of the amygdala GABAergic system. In control rats, administration of 5-HT or a-methyl-5-HT, a 5-HT 2 receptor agonist, to basolateral amygdala (BLA) slices dramatically enhanced frequency and amplitude of spontaneous inhibitory postsynaptic currents (sIPSCs). This effect was blocked by selective 5-HT 2A receptor antagonists while a selective 5-HT 2B receptor agonist and a selective 5-HT 2C receptor agonist were without effect on sIPSCs. Double immunofluorescence labeling demonstrated that the 5-HT 2A receptor is primarily localized to parvalbumin-containing BLA interneurons. Thus, serotonin primarily acts via 5-HT 2A receptors to facilitate BLA GABAergic inhibition. In stressed rats, the 5-HT 2A receptor-mediated facilitative actions were severely impaired. Quantitative RT-PCR and western blot analysis showed that the impairment of 5-HT 2A receptor signaling primarily resulted from receptor downregulation. The stress-induced effect appeared to be specific to 5-HT 2A receptors because stress had no significant impact on other serotonin receptors, as well as histamine H 3 receptor and a 2 adrenoceptor signaling in the BLA. This severe impairment of 5-HT 2A receptor-mediated facilitation of BLA GABAergic inhibition might result in an amygdala circuitry with hyperexcitability, and a lower threshold of activation, and thus be an important mechanism underlying the emergence of stress-associated psychiatric symptoms.

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Prolonged low-frequency stimulation of excitatory afferents to basolateral amygdala neurons results in enduring enhancement of excitatory synaptic responses. The induction of this form of synaptic plasticity is eliminated by selective antagonists of GluR5 kainate receptors and can be mimicked by the GluR5 agonist ATPA. Kainate receptor-mediated synaptic facilitation generalizes to include inactive afferent synapses on the target neurons, and therefore contrasts with other types of activity-dependent enduring synaptic facilitation that are input-pathway specific. Such heterosynaptic spread of synaptic facilitation could account for adaptive and pathological expansion in the set of critical internal and external stimuli that trigger amygdala-dependent behavioral responses.

Five-session rTMS treatment could best improve stroke-induced upper limb dyskinesia acutely and in a long-lasting manner. Intermittent theta burst stimulation is more beneficial than continuous theta burst stimulation. rTMS applied in the acute phase of stroke is more effective than rTMS applied in the chronic phase. Subcortical lesion benefit more from rTMS than other lesion site.

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Different types of psychosocial stressors have long been recognized as potential precipitants of both unipolar and bipolar affective episodes and the causative agents in posttraumatic stress disorder (PTSD). New preclinical data have revealed some of the neurobiological mechanisms that could convey the long-term behavioral and biochemical consequences of early stressors. Depending on the timing, quality, quantity, and degree of repetition, maternal deprivation stress in the neonatal rodent can be associated with lifelong anxiety-like behaviors, increases in stress hormones and peptides, and proneness to drug and alcohol administration, in association with acute changes in the rate of neurogenesis and apoptosis (preprogrammed cell death) and decrements in neurotrophic factors and signal transduction enzymes necessary for learning and memory. Patients with bipolar illness who have a history of early extreme adversity (physical or sexual abuse in childhood or adolescence), compared with those without, show an earlier onset of illness, faster cycling frequencies, increased suicidality, more Axis I and Axis II comorbidities (including alcohol and substance abuse), and more time ill in more than 2 years of prospective follow-up. These findings are subject to a variety of interpretations, but to the extent that the more severe course of bipolar illness characteristics are directly and causally related to these early stressful experiences, early recognition and treatment of high-risk children could be crucial in helping to prevent or ameliorate the long-term adverse consequences of these stressors.

This meta-analysis indicates that repetitive transcranial magnetic stimulation has a positive effect on dysphagia after stroke. Compared with low-frequency repetitive transcranial magnetic stimulation, high-frequency repetitive transcranial magnetic stimulation may be more beneficial to the patients. This meta-analysis also supports that repetitive transcranial magnetic stimulation on an unaffected - or bilateral - hemisphere has a significant therapeutic effect on dysphagia.

IntroductionTherapeutic effects of repetitive transcranial magnetic stimulation (rTMS) on motor recovery of Parkinson's disease (PD) have been reported; however, the protocols of these studies varied greatly. The aim of this meta‐analysis was to evaluate the optimal rTMS parameters for motor recovery of PD.MethodsElectronic databases were searched for studies investigating the therapeutic effects of rTMS on motor function in patients with PD. The section III of the Unified Parkinson's Disease Rating Scale (UPDRS) was extracted as the primary outcome, and the standardized mean difference (SMD) with 95% confidence interval (CI) was calculated.ResultsTwenty‐three studies with a total of 646 participants were included. The pooled estimates of rTMS revealed significant short‐term (SMD, 0.37; p < 0.00001) and long‐term (SMD, 0.39; p = 0.005) effects on motor function improvement of PD. Subgroup analysis observed that high‐frequency rTMS (HF‐rTMS) was significant in improving motor function (SMD, 0.48; p < 0.00001), but low‐frequency rTMS (LF‐rTMS) was not. In particular, when HF‐rTMS targeted over the primary motor cortex (M1), in which the bilateral M1 revealed a larger effect size than unilateral M1. Compared to single‐session, multi‐session of HF‐rTMS over the M1 showed significant effect size. In addition, HF‐rTMS over the M1 with a total of 18,000–20,000 stimulation pulses yielded more significant effects (SMD, 0.97; p = 0.01) than other dosages.ConclusionsIn conclusion, multi‐session of HF‐rTMS over the M1 (especially bilateral M1) with a total of 18,000–20,000 pulses appears to be the optimal parameters for motor improvement of PD.