Stress and behavioral correlates in the head-fixed method: stress measurements, habituation dynamics, locomotion, and motor-skill learning in mice.

Manual restriction of head movement, or head-fixation, of awake rodents allows for sophisticated investigation of neural circuits in vivo, that would otherwise be impossible in completely freely moving animals. While it is known that head-fixation induces stress, the scale of this stress and habituation dynamics remain unclear. We used the Mobile HomeCage system (Neurotar Ltd, Finland) where animals have their heads fixed to an aluminum frame but are otherwise freely moving in an ultralight carbon container floating above an air-dispensing base.

Parallel, but Dissociable, Processing in Discrete Corticostriatal Inputs Encodes Skill Learning.

Changes in cortical and striatal function underlie the transition from novel actions to refined motor skills. How discrete, anatomically defined corticostriatal projections function in vivo to encode skill learning remains unclear. Using novel fiber photometry approaches to assess real-time activity of associative inputs from medial prefrontal cortex to dorsomedial striatum and sensorimotor inputs from motor cortex to dorsolateral striatum, we show that associative and sensorimotor inputs co-engage early in action learning and disengage in a dissociable manner as actions are refined.

The non-coding RNA BC1 regulates experience-dependent structural plasticity and learning.

The brain cytoplasmic (BC1) RNA is a non-coding RNA (ncRNA) involved in neuronal translational control. Absence of BC1 is associated with altered glutamatergic transmission and maladaptive behavior. Here, we show that pyramidal neurons in the barrel cortex of BC1 knock out (KO) mice display larger excitatory postsynaptic currents and increased spontaneous activity in vivo.

Somatosensory map expansion and altered processing of tactile inputs in a mouse model of fragile X syndrome.

Fragile X syndrome (FXS) is a common inherited form of intellectual disability caused by the absence or reduction of the fragile X mental retardation protein (FMRP) encoded by the FMR1 gene. In humans, one symptom of FXS is hypersensitivity to sensory stimuli, including touch. We used a mouse model of FXS (Fmr1 KO) to study sensory processing of tactile information conveyed via the whisker system.

NEURODEVELOPMENT. Adult cortical plasticity depends on an early postnatal critical period.

Development of the cerebral cortex is influenced by sensory experience during distinct phases of postnatal development known as critical periods. Disruption of experience during a critical period produces neurons that lack specificity for particular stimulus features, such as location in the somatosensory system. Synaptic plasticity is the agent by which sensory experience affects cortical development.