The major cranial vibrissae in the golden hamster can be moved in complex ways that suggest they are served by a finely controlled motor system. Movements are hypothesized to be the products of differential blood flow and pressure regulation in the sinus surrounding each vibrissal follicle, contractions of the striated facial muscles, and elastic rebound in the connective tissues. The vasculature contributes hydrostatic forces that erect the vibrissae slightly and distort their connective tissue bedding, rigidify the vibrissal capsules, thus forming firm bases of attachment for certain facial muscles, and theoretically provide a pressure plate around the follicle, important in lowering the firing thresholds of receptor endings. The facial muscles supply the major forces in erection and protraction of the vibrissae by acting on both the capsules and the connective tissue bedding. The connective tissues are organized into capsular and extracapsular systems that serve to stabilize the vibrissae and return them to initial rest positions. The slight movements of the genal vibrissa are the effects of vascular and connective tissue dynamics, the musculature being uninvolved. Wide angle movements of the supraorbital vibrissae are products of the vasculature and connective tissues, plus contractions of the Mm. orbicularis oculi and frontalis. Mystacial vibrissal movement is quite complex. The vasculature supplies a small degree of capsular erection and mystacial pad distortion, but primarily rigidifies the capsules. The bulk of erection and protraction is produced by the M. nasolabialis profundus (NLP) and the vibrissal capsular muscles (VCM). The NLP distorts the mystacial pad; the VCM tilt the capsules relative to the pad. Retraction is mainly accomplished by elastic rebound in the pad, this being aided in its extreme degrees by the Mm. nasolabialis and maxillolabialis. The Mm. nasolabialis superficialis and buccinator pars orbicularis oris help to spread the vibrissae into a dorsoventral fan and stabilize the mystacial pad during whisking.

During mastication the adult pig masseter contracts with a complex pattern involving a wave of electromyographic (EMG) activity moving from the ventro-rostral corner to the dorso-caudal corner. The present study was undertaken to ascertain the ontogeny of that contraction pattern. Anatomical measurements were made on masseters from fetal, infant, and juvenile pigs. EMG activity from different parts of the masseter was recorded along with oral movements in infant and juvenile pigs as they suckled, drank, and chewed on food and non-food objects. The basic arrangement of muscle fibers and tendinous aponeuroses was found to be the same in all ages. The longest and most vertical fibers were found rostrally and ventrally, whereas the shortest and most horizontal fibers were found caudally and dorsally. The length of fasciculi decreased with age, relative to muscle weight. Variance in length among different parts of the muscle increased with age. Fetal masseters were oriented generally more horizontally than the masseters of older animals, except that the dorso-caudal corner, usually the most horizontal portion, is not developed in fetuses. The contraction patterns within the infant masseter were less complex than those of older animals; only the dorso-caudal corner was distinct. The further development of intramuscular differences in activity may be associated with the increasing anatomical complexity of the masseter, which augments its functional capabilities.

Morehouse School of Medicine chose to restructure its first year medical curriculum in 2005. The anatomy faculty had prior experience in integrating courses, stemming from the successful integration of individual anatomical sciences courses into a single course called Human Morphology. The integration process was expanded to include the other first year basic science courses (Biochemistry, Physiology, and Neurobiology) as we progressed toward an integrated curriculum. A team, consisting of the course directors, a curriculum coordinator and the Associate Dean for Educational and Faculty Affairs, was assembled to build the new curriculum. For the initial phase, the original course titles were retained but the lecture order was reorganized around the Human Morphology topic sequence. The material from all four courses was organized into four sequential units. Other curricular changes included placing laboratories and lectures more consistently in the daily routine, reducing lecture time from 120 to 90 minute blocks, eliminating unnecessary duplication of content, and increasing the amount of independent study time. Examinations were constructed to include questions from all courses on a single test, reducing the number of examination days in each block from three to one. The entire restructuring process took two years to complete, and the revised curriculum was implemented for the students entering in 2007. The outcomes of the restructured curriculum include a reduction in the number of contact hours by 28%, higher or equivalent subject examination average scores, enhanced student satisfaction, and a first year curriculum team better prepared to move forward with future integration.

Vibrissae are highly refined vibrotactile receptors that are present on most mammals. The Golden hamster exhibits three different behaviours of its mystacial, supraorbital, and genal vibrissae. During rest, all the vibrissae are reclined and motionless. When hamsters are alert, the vibrissae are partly or fully erect and essentially motionless. During active investigation, the mystacial vibrissae “whisk” or “sweep” through antero–posterior excursions. The genal vibrissa moves only slightly in periodic erection. The supraorbital vibrissae carry through a wide erection arc and have limited excursions with movements of the upper eyelid. The mystacial vibrissae whisk quickly (about 16 sweepsls). Whisking is divisible into contact (relatively high amplitude, low frequency), non–contact (relatively low amplitude, high frequency), and double–pump (combination contact and non–contact) types, and can be either bilaterally symmetric or asymmetric. The dimensions of the mystacial territory around the snout change throughout whisking due to coordinated changes in the shape of the mystacial pad and the tilting of the vibrissae relative to the pad. Such differential movements have implications for sensory physiology as they point to an ability for fine sensory monitoring of the environment.

Anabolic agents are useful tools for probing the mechanisms by which muscle fibers perceive and respond to disuse. β₂-Adrenergic agonists exert protective, and/or reparative, effects on atrophying muscle tissue. The effects of one such agent, clenbuterol (Cb), were examined on muscle mass, total protein content, and myofibrillar protein content in selected hindlimb muscles [adductor longus (ADL), extensor digitorum longus (EDL), plantaris (PLAN), soleus (SOL)] of mature male rats, under different loading conditions. Pair-fed rats were divided into four experimental groups: vehicle- and Cb-treated nonsuspended, vehicle- and Cb-treated hindlimb suspended (HLS). Experiments lasted 14 days, during which the rats received subcutaneous injections of 1 mg/kg Cb or 1 ml/kg vehicle. HLS induced significant atrophy in all muscles, except the EDL, in a generally fiber type-related pattern. However, myofibrillar protein content was affected in a more regional pattern. Cb treatment of nonsuspended rats induced hypertrophy in all muscles, in a generally uniform pattern. However, myofibrillar protein content was affected in a more fiber type-related pattern. Cb treatment of HLS rats reduced or eliminated HLS-induced atrophy in all muscles, in a muscle-specific pattern. Overall, the ADL and SOL were most susceptible to HLS-induced atrophy. The PLAN had the greatest magnitude of Cb-induced sparing of atrophy. The results show that, in mature male rats, Cb exerts anabolic effects that are load-dependent and muscle-specific. Responses to this drug cannot be reliably predicted by fiber-type composition alone.