The clearance of Ca 2ϩ from nerve terminals is critical for determining the build-up of residual Ca 2ϩ after repetitive presynaptic activity. We found previously that K

Background Asians increasingly seek non-surgical facial esthetic treatments, especially at younger ages. Published recommendations and clinical evidence mostly reference Western populations, but Asians differ from them in terms of attitudes to beauty, structural facial anatomy, and signs and rates of aging. A thorough knowledge of the key esthetic concerns and requirements for the Asian face is required to strategize appropriate facial esthetic treatments with botulinum toxin and hyaluronic acid (HA) fillers.MethodsThe Asian Facial Aesthetics Expert Consensus Group met to develop consensus statements on concepts of facial beauty, key esthetic concerns, facial anatomy, and aging in Southeastern and Eastern Asians, as a prelude to developing consensus opinions on the cosmetic facial use of botulinum toxin and HA fillers in these populations.ResultsBeautiful and esthetically attractive people of all races share similarities in appearance while retaining distinct ethnic features. Asians between the third and sixth decades age well compared with age-matched Caucasians. Younger Asians’ increasing requests for injectable treatments to improve facial shape and three-dimensionality often reflect a desire to correct underlying facial structural deficiencies or weaknesses that detract from ideals of facial beauty.ConclusionsFacial esthetic treatments in Asians are not aimed at Westernization, but rather the optimization of intrinsic Asian ethnic features, or correction of specific underlying structural features that are perceived as deficiencies. Thus, overall facial attractiveness is enhanced while retaining esthetic characteristics of Asian ethnicity. Because Asian patients age differently than Western patients, different management and treatment planning strategies are utilized.Level of Evidence VThis journal requires that authors assign a level of evidence to each article. For a full description of these Evidence-Based Medicine ratings, please refer to Table of Contents or the online Instructions to Authors www.springer.com/00266.

At the immature calyx of Held, the fast decay phase of a Ca 2ϩ transient induced by tetanic stimulation (TS) was followed by a period of elevated [Ca 2ϩ ] i for tens of seconds, referred to as posttetanic residual calcium (Ca res ). We investigated the source of Ca res and its contribution to posttetanic potentiation (PTP). After TS (100 Hz for 4 s), posttetanic Ca res at the calyx of Held was largely abolished by tetraphenylphosphonium (TPP ϩ ) or Ru360, which inhibit mitochondrial Na ϩ -dependent Ca 2ϩ efflux and Ca 2ϩ uniporter, respectively. Whereas the control PTP lasted longer than Ca res , inhibition of Ca res by TPP ϩ resulted in preferential suppression of the early phase of PTP, the decay time course of which well matched with that of Ca res . TS induced significant increases in release probability (P r ) and the size of the readily releasable pool (RRP), which were estimated from plots of cumulative EPSC amplitudes. TPP ϩ or Ru360 suppressed the posttetanic increase in P r , whereas it had little effect on the increase in RRP size. Moreover, the posttetanic increase in P r , but not in RRP size, showed a linear correlation with the amount of Ca res . In contrast, myosin light chain kinase (MLCK) inhibitors and blebbistatin reduced the posttetanic increase in RRP size with no effect on the increase in P r . Application of TPP ϩ in the presence of MLCK inhibitor peptide caused further suppression of PTP. These findings suggest that Ca res released from mitochondria and activation of MLCK are primarily responsible for the increase in P r and that in the RRP size, respectively.

Glutamatergic synaptic terminals harbor reluctant synaptic vesicles (SVs) that contribute little to synchronous release during action potentials but are release competent when stimulated by sucrose or by direct intracellular application of calcium. It has been noted that the proximity of a release-competent SV to the calcium source is one of the primary factors that differentiate reluctant SVs from fastreleasing ones at the calyx of Held synapse. It has not been known whether reluctant SVs can be converted into fast-releasing ones. Here we show that reluctant SVs are recruited rapidly in an actindependent manner to become fast-releasing SVs once the pool of fast-releasing SVs is depleted by a short depolarization. Recovery of the pool of fast-releasing SVs was accompanied by a parallel reduction in the number of reluctant SVs. Quantitative analysis of the time course of depletion of fast-releasing SVs during high-frequency stimulation revealed that in the early phase of stimulation reluctant SVs are converted rapidly into fast-releasing ones, thereby counteracting short-term depression. During the late phase, however, after reluctant vesicles have been used up, another process of calmodulindependent recruitment of fast-releasing SVs is activated. These results document that reluctant SVs have a role in short-term plasticity and support the hypothesis of positional priming, which posits that reluctant vesicles are converted into fast-releasing ones via relocation closer to Ca 2+ -channels.readily releasable pool | synaptic vesicle dynamics S ynaptic strength is determined by quantal size, the number of release-competent synaptic vesicles (SVs), and their release probability (Pr). The estimate for the number of release-competent SVs, which also is referred to as the "readily releasable pool (RRP) size," depends heavily on the method used for its determination. The RRP size estimated by a cumulative plot of the excitatory postsynaptic currents (EPSC) amplitudes evoked by high-frequency afferent fiber stimulation (RRP cum ) is smaller than that estimated by the application of a hypertonic sucrose solution or presynaptic strong depolarization (1-3). This discrepancy reflects the presence of reluctant SVs, which are scarcely released by an action potential (AP) at glutamatergic synaptic terminals. Consistently, deconvolution analysis of EPSCs evoked by a long depolarizing pulse at the calyx of Held revealed that release-competent SVs can be separated into fast-and slowreleasing SV pools (FRP and SRP, respectively) (4). The FRP vesicles are responsible for phasic release during a high-frequency train of action potentials (APs), whereas the SRP vesicles contribute primarily to asynchronous release, when the intracellular concentration of calcium ions ([Ca 2+ ]) is increased globally during the late period of the train (2). Thus, SRP vesicles can be regarded largely as reluctant SVs at the calyx of Held.Despite the evidence for the presence of reluctant SVs at glutamatergic synapses, their role in short-term plasticity i...