Based on these observations, we now provide a conceptual framework for considering how induction of autophagy during starvation functions to mobilize neuronal lipids for the controlled availability of neuron-intrinsic free fatty acids, which upregulate AgRP levels and increase food intake specifically in response to starvation [ 36].
Therefore our data suggest that MHC II expression correlates with the availability of neurons and fibers expressing α-syn.
In fact, findings from a recent study suggest that the availability of neuron-intrinsic free fatty acids and its metabolism may provide the bioenergetic requirements for hypothalamic neuronal activation and firing [ 56].
Limited availability of human neurons poses a significant barrier to progress in biological and preclinical studies of the human nervous system.
Second, levels of adult neurogenesis decline exponentially with age and are regulated by a large number of genetic and environmental factors: Does the availability of new neurons affect their rate of incorporation?
Unlike the complete absence of auditory signals, however, this increase in proliferating Sox2-positive cells was not followed by an increased availability of immature neurons.
Whether gain-of-function mutations in Kir2.1 enhance the availability of Nav1.5 in neurons, and if this mechanism might contribute to lowering the threshold for seizures\ASD remains an intriguing hypothesis.
It is yet to be determined whether astrocytic leptin receptor expression or signaling compromise the availability of leptin to ObR+ neurons, or whether secondary signals from leptin modulate neuronal leptin activities.
The limited availability of fibroblasts and differentiated neurons did not allow for biochemical studies or more indepth analyses.
Therefore changes in the concentration or availability of iron within these neurons will additionally impact on mitochondrial function and could thus exacerbate any mitochondrial dysfunction further, leading to a loss of these neurons.
The availability of iPSC-derived human neurons with GGGGCC repeat expansions in patients' native genetic context will serve as a compelling model to further investigate underlying pathogenic mechanisms and broaden our knowledge of this devastating disease.
