Neocortical layer 5 subclasses: From cellular properties to roles in behavior.

Layer 5 (L5) serves as the main output layer of cortical structures, where long-range projecting pyramidal neurons broadcast the columnar output to other cortical and extracortical regions of the brain. L5 pyramidal neurons are grouped into two subclasses based on their projection targets; while intratelencephalic (IT) neurons project to cortical areas and the striatum, extratelencephalic (ET) neurons project to subcortical areas such as the thalamus, midbrain, and brainstem. Each L5 subclass possesses distinct morphological and electrophysiological properties and is incorporated into a unique synaptic network.

Thalamic input to motor cortex facilitates goal-directed action initiation.

Prompt execution of planned motor action is essential for survival. The interactions between frontal cortical circuits and the basal ganglia are central to goal-oriented action selection and initiation. In rodents, the ventromedial thalamic nucleus (VM) is one of the critical nodes that conveys the output of the basal ganglia to the frontal cortical areas including the anterior lateral motor cortex (ALM).

Active dendritic currents gate descending cortical outputs in perception.

The output of cortical columns is routed to different downstream targets via distinct pathways: cortico-cortical and cortico-subcortical. It is as yet unclear what roles these pathways play in perception, and which cellular and circuit mechanisms regulate their gating. We recently showed that activation of the apical dendrites of layer 5 (L5) pyramidal neurons correlates with the threshold for perception, but these neurons come in two classes that target either other cortical or subcortical areas.

Memory formation in the absence of experience.

Memory is coded by patterns of neural activity in distinct circuits. Therefore, it should be possible to reverse engineer a memory by artificially creating these patterns of activity in the absence of a sensory experience. In olfactory conditioning, an odor conditioned stimulus (CS) is paired with an unconditioned stimulus (US; for example, a footshock), and the resulting CS-US association guides future behavior.

Serum fatty acids in infants, reflecting family fish consumption, were inversely associated with allergy development but not related to farm residence.

Aim: In this study, differences in serum fatty acid patterns between farm and nonfarm infants were investigated and related to subsequent allergy development. We also related allergy-related serum fatty acids to maternal diet and breast milk fatty acids.

Methods: The FARMFLORA birth cohort included 28 farm and 37 nonfarm infants.

Fat intake and breast milk fatty acid composition in farming and nonfarming women and allergy development in the offspring.

Background: Children growing up on small family farms are at much lower risk of developing allergy than other children. We hypothesized that low intake of margarine and polyunsaturated fats among farming families could contribute to this protection.

Methods: Twenty-eight mother-infant pairs living on small dairy farms and 37 nonfarm rural resident pairs were recruited in the FARMFLORA birth cohort.

Surfactant protein A and D gene polymorphisms and protein expression in victims of sudden infant death.

Aim: To investigate the innate immune components surfactant protein A (SP-A) and D (SP-D) in victims of sudden infant death syndrome (SIDS).

Methods: Ten common single nucleotide polymorphisms (SNPs) in the exons of SP-A1, SP-A2 and SP-D genes were analysed in 42 cases of SIDS and 46 explained sudden infant deaths. SP-A and SP-D protein expression in tissue from the aerodigestive tract was semi-quantitatively evaluated by immunohistochemistry.