Dopamine injections to the midbrain periaqueductal gray inhibit vocal-motor production in a teleost fish.

Across vertebrates, the midbrain periaqueductal gray (PAG) plays a critical role in social and vocal behavior. Dopaminergic neurotransmission also modulates these behaviors, and dopaminergic innervation of the PAG has been well documented. Nonetheless, the potential role of dopamine in shaping vocal production at the level of the PAG is not well understood.

Ca entry units in a superfast fish muscle.

Over the past two decades, mounting evidence has demonstrated that a mechanism known as store-operated Ca entry (SOCE) plays a crucial role in sustaining skeletal muscle contractility by facilitating Ca influx from the extracellular space during sarcoplasmic reticulum (SR) Ca depletion. We recently demonstrated that, in exercised fast-twitch muscle from mice, the incidence of Ca entry units (CEUs), newly described intracellular junctions between dead-end longitudinal transverse tubular (T-tubule) extensions and stacks of sarcoplasmic reticulum (SR) flat cisternae, strictly correlate with both the capability of fibers to maintain contractions during fatigue and enhanced Ca influx SOCE. Here, we tested the broader relevance of this result across vertebrates by searching for the presence of CEUs in the vocal muscles of a teleost fish adapted for extended, high-frequency activity.

A simple and robust LC-ESI single quadrupole MS-based method to analyze neonicotinoids in honey bee extracts.

Over the past years, neonicotinoids such as thiacloprid and flupyradifurone have gained considerable scientific and public interest. These molecules used as active compounds in pesticides are known due to cause drastic negative long-time effects on pollinators and even human health. Therefore, determining trace amounts of neonicotinoid in different environmental matrices by liquid chromatography coupled with mass selective detectors (LC-MS/MS or LC-Q-TOF/MS) has become an important methodology.

Sexually-dimorphic expression of tyrosine hydroxylase immunoreactivity in the brain of a vocal teleost fish (Porichthys notatus).

Vocal communication has emerged as a powerful model for the study of neural mechanisms of social behavior. Modulatory neurochemicals postulated to play a central role in social behavior, related to motivation, arousal, incentive and reward, include the catecholamines, particularly dopamine and noradrenaline. Many questions remain regarding the functional mechanisms by which these modulators interact with sensory and motor systems.

Vocal-motor and auditory connectivity of the midbrain periaqueductal gray in a teleost fish.

The midbrain periaqueductal gray (PAG) plays a central role in the descending control of vocalization across vertebrates. The PAG has also been implicated in auditory-vocal integration, although its precise role in such integration remains largely unexplored. Courtship and territorial interactions in plainfin midshipman fish depend on vocal communication, and the PAG is a central component of the midshipman vocal-motor system.

Midbrain periaqueductal gray and vocal patterning in a teleost fish.

Midbrain structures, including the periaqueductal gray (PAG), are essential nodes in vertebrate motor circuits controlling a broad range of behaviors, from locomotion to complex social behaviors such as vocalization. Few single-unit recording studies, so far all in mammals, have investigated the PAG's role in the temporal patterning of these behaviors. Midshipman fish use vocalization to signal social intent in territorial and courtship interactions.

Acute injections of brain-derived neurotrophic factor in a vocal premotor nucleus reversibly disrupt adult birdsong stability and trigger syllable deletion.

Behavioral variability serves an essential role in motor learning by enabling sensory feedback to select those motor patterns that minimize error. Birds use auditory feedback to learn how to sing, and their songs lose variability and become highly stereotyped, or crystallized, at the end of a sensitive period for sensorimotor learning. The molecular cues that regulate song variability are not well understood.

Lesions of an avian forebrain nucleus that disrupt song development alter synaptic connectivity and transmission in the vocal premotor pathway.

The avian forebrain nucleus, the lateral magnocellular nucleus of the anterior neostriatum (LMAN), is necessary for normal song development because LMAN lesions made in juvenile birds disrupt song production but do not disrupt song when made in adults. Although these age-limited behavioral effects implicate LMAN in song learning, a potential confound is that LMAN lesions could disrupt normal vocal motor function independent of any learning role by altering LMAN's premotor target, the song nucleus, the robust nucleus of the archistriatum (RA). To date, however, no studies have examined directly the effects of LMAN lesions on the circuitry of the RA.

Corruption of genomic databases with anomalous sequence.

We describe evidence that DNA sequences from vectors used for cloning and sequencing have been incorporated accidentally into eukaryotic entries in the GenBank database. These incorporations were not restricted to one type of vector or to a single mechanism. Many minor instances may have been the result of simple editing errors, but some entries contained large blocks of vector sequence that had been incorporated by contamination or other accidents during cloning.