• Differential expression analysis of Liprin-a2 in hibernating bat (Rhinolophus ferrumequinum)

    Subjects: Biology >> Biomedical Laboratory Science submitted time 2017-05-10

    Abstract:A PCR-based subtractive hybridization technique was used to identify genes up-regulated in the hibernating bat brain to explore the molecular mechanism of hibernation. Three genes, Liprin-a2, PTP4A2 and CAMKKb were differentially expressed in hibernating bat brain tissue compared to active bat brain tissue. One of them, Liprin-a2, which has recently been shown to have the key function in the organization of presynaptic and postsynaptic multiprotein complexes was studied in detail. We demonstrated that the expression level of Liprin-a2 was up-regulated almost 4-fold in hibernating bat brains by RT-PCR compared to levels in active bats. The differential expression pattern of Liprin-a2 was also detected in muscle, fat, brain and heart tissue of hibernating bats by real-time quantitative PCR. The result indicated that Liprin-a2 was over-expressed in brain and heart tissue and down-regulated in muscle and fat. In brain tissue of hibernating bats, Liprin-a2 expression was statistically significantly higher than in brain tissue of active controls (P = 0.029). The precise control of transcriptional level and the distinctively differential expression pattern of Liprin-a2 in different organs during circannual hibernation may have important physiological significance, not only in maintaining normal function of many key organs but also in effectively conserving limited energy resources without physiological damage.

  • A mechanism for vocal-respiratory coupling in the mammalian parabrachial nucleus

    Subjects: Biology >> Biomedical Laboratory Science submitted time 2017-03-30

    Abstract: Mammalian vocalizations require the precise coordination of separate laryngeal and respiratory motor pathways. Precisely how and where in the brain vocal motor patterns interact with respiratory rhythm control is unknown. The parabrachial nucleus (PB) is known to mediate key respiratory reflexes and is also considered a principle component of the mammalian vocal motor pathway, making it a likely site for vocal–respiratory interactions, yet a specific role for the PB in vocalizing has yet to be demonstrated. To investigate the role of the PB in vocal–respiratory coordination, we pharmacologically manipulated synaptic activity in the PB while spontaneously vocalizing horseshoe bats were provoked to emit either short, single syllable or long, multisyllabic vocal motor patterns. Iontophoresis of theGABAA agonist muscimol (MUS) into the lateral PB extended expiratory durations surrounding all vocalizations and increased mean call durations. Alternatively, application of the GABAA antagonist bicuculline methiodide (BIC) shortened expirations and call durations. In addition, BIC eliminated the occurrence of multisyllabic vocalizations. BIC caused a mild increase in quiet breathing rates, whereasMUS tended to slow quiet breathing. The results indicate thatGABAA receptor-mediated inhibition in the lateral PB modulates the time course of respiratory phase switching during vocalizing, and is needed for proper coordination of calling and breathing in mammals. We hypothesize that vocal–respiratory rhythm entrainment is achieved at least in part via mechanisms similar to other forms of locomotorrespiratory coupling, namely somatosensory feedback influences on respiratory phase-switching in the lateral PB.