A Transdisciplinary Program for Care of Veterans With Neurocognitive Disorders.

Background: Veterans face specific risk factors for neurocognitive disorders. Providing them with comprehensive care for dementia and related neurocognitive disorders is a challenge as the population ages. There is a need for family-centered interventions, specialized expertise, and collaboration among clinicians and caregivers. The literature suggests that application of a transdisciplinary care model can address these needs and provide effective dementia care. Observations: The Veterans Affairs Greater Los Angeles Healthcare System has employed existing expertise to create a conference-centered transdisciplinary model that responds to the US Department of Veterans Affairs directive for a dementia system of care. This model involves direct participation of behavioral neurology, geriatric psychiatry, geriatrics, neuropsychology, nursing, and social work. In this model, the social worker serves as a dementia care manager and, along with the nurse specialist, assures long-term management through follow-up and monitoring. Transdisciplinary interactions occur in a clinical case conference where each discipline contributes to the veteran's care. The team generates a final report on treating these veterans, the caregiver's needs, referral for psychosocial services, and plans for monitoring and follow-up. Conclusions: This model could be a template of a program for implementing the Dementia System of Care across Veteran Affairs medical centers.

Mapping the vocal circuitry of Alston's singing mouse with pseudorabies virus.

Vocalizations are often elaborate, rhythmically structured behaviors. Vocal motor patterns require close coordination of neural circuits governing the muscles of the larynx, jaw, and respiratory system. In the elaborate vocalization of Alston's singing mouse (Scotinomys teguina) each note of its rapid, frequency-modulated trill is accompanied by equally rapid modulation of breath and gape. To elucidate the neural circuitry underlying this behavior, we introduced the polysynaptic retrograde neuronal tracer pseudorabies virus (PRV) into the cricothyroid and digastricus muscles, which control frequency modulation and jaw opening, respectively. Each virus singly labels ipsilateral motoneurons (nucleus ambiguus for cricothyroid, and motor trigeminal nucleus for digastricus). We find that the two isogenic viruses heavily and bilaterally colabel neurons in the gigantocellular reticular formation, a putative central pattern generator. The viruses also show strong colabeling in compartments of the midbrain including the ventrolateral periaqueductal gray and the parabrachial nucleus, two structures strongly implicated in vocalizations. In the forebrain, regions important to social cognition and energy balance both exhibit extensive colabeling. This includes the paraventricular and arcuate nuclei of the hypothalamus, the lateral hypothalamus, preoptic area, extended amygdala, central amygdala, and the bed nucleus of the stria terminalis. Finally, we find doubly labeled neurons in M1 motor cortex previously described as laryngeal, as well as in the prelimbic cortex, which indicate these cortical regions play a role in vocal production. The progress of both viruses is broadly consistent with vertebrate-general patterns of vocal circuitry, as well as with circuit models derived from primate literature.

Motor cortical control of vocal interaction in neotropical singing mice.

Like many adaptive behaviors, acoustic communication often requires rapid modification of motor output in response to sensory cues. However, little is known about the sensorimotor transformations that underlie such complex natural behaviors. In this study, we examine vocal exchanges in Alston's singing mouse (Scotinomys teguina). We find that males modify singing behavior during social interactions on a subsecond time course that resembles both traditional sensorimotor tasks and conversational speech. We identify an orofacial motor cortical region and, via a series of perturbation experiments, demonstrate a hierarchical control of vocal production, with the motor cortex influencing the pacing of singing behavior on a moment-by-moment basis, enabling precise vocal interactions. These results suggest a systems-level framework for understanding the sensorimotor transformations that underlie natural social interactions.

Population-Level Representation of a Temporal Sequence Underlying Song Production in the Zebra Finch.

The zebra finch brain features a set of clearly defined and hierarchically arranged motor nuclei that are selectively responsible for producing singing behavior. One of these regions, a critical forebrain structure called HVC, contains premotor neurons that are active at precise time points during song production. However, the neural representation of this behavior at a population level remains elusive. We used two-photon microscopy to monitor ensemble activity during singing, integrating across multiple trials by adopting a Bayesian inference approach to more precisely estimate burst timing. Additionally, we examined spiking and motor-related synaptic inputs using intracellular recordings during singing. With both experimental approaches, we find that premotor events do not occur preferentially at the onsets or offsets of song syllables or at specific subsyllabic motor landmarks. These results strongly support the notion that HVC projection neurons collectively exhibit a temporal sequence during singing that is uncoupled from ongoing movements.