No abstract

1. The contribution of the midbrain periaqueductal gray (PAG) to the central regulation of vocalization was investigated by analyzing the electromyographic (EMG) changes in respiratory, laryngeal, and oral muscles evoked by microinjection of D,L-homocysteic acid (DLH) in the PAG of unanesthetized, precollicular decerebrate cats. Moderate to large (6-40 nmol) doses of DLH evoked natural-sounding vocalization as well as increases in inspiratory depth and respiratory rate. 2. Two basic types of vocalization were evoked, each associated with a distinct and characteristic pattern of respiratory, laryngeal and oral EMG changes. Type A vocalization (voiced sounds such as howl/mew/growl) was characterized by excitation of the cricothyroid (CT) and thyro-arytenoid (TA) muscles, and inhibition of the posterior crico-arytenoid (PCA) muscle, whereas type B vocalization (unvoiced hiss sounds) was characterized by excitation of the PCA and TA muscles and no significant activation of the CT muscle. In addition, stronger expiratory (external oblique, internal oblique, internal intercostal) EMG increases were associated with type A responses, and larger increases in genioglossus and digastric muscle activity were associated with type B responses. 3. Microinjections of small doses of DLH (300 pmol-3 nmol), also evoked patterned changes in muscle activity (usually without audible vocalization) that, although of lower amplitude, were identical to those evoked by injections of moderate to large DLH doses. In no such experiments (175 sites) were individual muscles activated by small dose injections of DLH into the PAG. Further, type A vocalization/muscle patterns were evoked from PAG sites caudal to those at which type B vocalization/muscle patterns were evoked. 4. Considered together these results indicate: that the PAG contains topographically separable groups of neurons that coordinate laryngeal, respiratory, and oral muscle patterns characteristic of two fundamental types of vocalization and that the underlying PAG organization takes the form of a representation of muscle patterns, rather than individual muscles. 5. The patterns of EMG activity evoked by excitation of PAG neurons were strikingly similar to previously reported patterns of EMG activity characteristic of major phonatory categories in higher species, including humans (e.g., vowel phonation, voiceless consonant phonation). These findings raise the possibility that the sound production circuitry of the PAG could well be utilized by cortical and subcortical "language structures" to coordinate basic respiratory and laryngeal motor patterns that are necessary for speech.

Previous randomized controlled trials (RCTs) have shown that acupuncture may be efficacious for insomnia. Instead of needling, acupressure, reflexology, and auricular acupressure are procedures involving physical pressure on acupoints or reflex areas. These variants of acupuncture are gaining popularity, perhaps due to their non-invasive nature. A systematic review has therefore been conducted to examine their efficacy and safety for insomnia. Two independent researchers searched five English and 10 Chinese databases from inception to May 2010. Forty RCTs were identified for analysis. Only 10 studies used sham controls, four used double-blind design, nine studies scored three or more by the Jadad scale, and all had at least one domain with high risk of bias. Meta-analyses of the moderate-quality RCTs found that acupressure as monotherapy fared marginally better than sham control. Studies that compared auricular acupressure and sham control showed equivocal results. It was also found that acupressure, reflexology, or auricular acupressure as monotherapy or combined with routine care was significantly more efficacious than routine care or no treatment. Owing to the methodological limitations of the studies and equivocal results, the current evidence does not allow a clear conclusion on the benefits of acupressure, reflexology, and auricular acupressure for insomnia.

We found a slight advantage of electroacupuncture over placebo acupuncture in the short-term treatment of primary insomnia. Because of some limitations of the current study, further studies are necessary to verify the effectiveness of acupuncture for insomnia.

1. The descending pathways that mediate the periaqueductal gray (PAG)-evoked coordination of respiratory, laryngeal, and orofacial activity for vocalization have yet to be delineated. Two hypotheses have been offered. One theory is that this activity is mediated by a diffuse descending projection to parvocellular reticular interneurons, adjacent to the relevant laryngeal and orofacial motoneuronal pools. The second hypothesis is that the motor activity for vocalization is integrated via a projection from the PAG to a caudal medullary column of neurons, the nucleus retroambigualis (NRA). These hypotheses were tested with the use of a series of medullary transections combined with PAG stimulation. Transections that eliminated, in a series of caudal-to-rostral steps, the NRA, also eliminated the PAG-evoked cricothyroid and most of the thyroarytenoid laryngeal motor activity. These results indicate that the final common pathway for much of the laryngeal activity in PAG-evoked vocalization includes un initial synapse in the caudal medulla, presumably in the NRA. 2. The electromyographic changes evoked by microinjection of D,L-homocysteic acid (DLH) in the NRA of the unanesthetized, precollicular decerebrate cat were analyzed in order to delineate the NRA contribution to the coordinated respiratory, laryngeal, and oral muscle changes in vocalization. A total of 415 DLH injection sites were located at or caudal to the level of the obex. Vocalization was evoked at 46 of these sites, which were all confined to a restricted region of the ventrolateral medulla 1-3 mm caudal to the obex. This region corresponded to the rostral half of the NRA and the immediately adjacent medullary tegmentum. 3. In all experiments evidence was obtained that variable muscle activation, rather than functional and integrated muscle patterns, was represented within the NRA. Vocalization evoked by DLH microinjection in the NRA was usually associated with excitation of the cricothyroid, thyroarytenoid, external oblique, internal oblique, internal intercostal, and diaphragm muscles that occurred in a different manner from site to site. That is, injection at sites separated by 0.3-0.5 mm evoked quite different responses. 4. NRA-evoked vocalization was compared with PAG-evoked vocalization using small injections (1.5-4.5 nl) into each region. As well, larger microinjections (15-120 nl) into NRA were made for comparison with previous results from the PAG using similar doses. Within the PAG, stereotyped and relatively "fixed" patterns of muscle activity are represented, whereas within the NRA there was no representation of specific muscle patterns, but rather a partial topographic separation of "premotor neurons" regulating different muscles. Correspondingly, stereotyped vocalizations were never evoked from the NRA. Further, most NRA-evoked vocalizations were unusual in quality and would not be identified generally as feline. 5. Evidence was obtained for a separation of pathways from the PAG regulating sound production and orofacial modulation of that s...