Charles Hoeffer

Nicotine doesn’t just affect neurons, it rapidly flips on astrocyte-specific AKT2 signaling in vivo and drives striking, AKT2-dependent remodeling of astrocyte morphology, linking glial activation to the brain’s acute nicotine response. We show nicotine’s astrocyte effects are mediated by astrocytic nicotinic receptors (α7 in vivo, and either α7 or α4β2 in vitro), and that AKT2’s role shifts with exposure history: robust responses to acute nicotine versus an unexpected blunting/atrophy-like pattern after chronic exposure. Importantly, disrupting astrocytic AKT2 alters nicotine conditioned place preference, tying a glial AKT2 pathway to nicotine reward and positioning astrocytes, and AKT2 specifically, as a new mechanistic lever in nicotine use disorders.

(Glia, 2025)

We differentiated human-induced pluripotent stem cells (hiPSCs)into neurons and co-cultured with primary human astrocytes to achieve robust neural network within six weeks, significantly faster than 3D brain organoids. This efficient, fully human co-culture system, paired with multielectrode arrays (MEAs), provides a powerful and high-throughput platform for studying neuronal network properties, blood-brain barrier dynamics, and neurodegenerative diseases.

(PLOS ONE, 2024)

Transactive response DNA binding protein 43 kilodaltons (TDP-43) is a DNA and RNA binding protein associated with severe neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), primarily affecting motor neurons in the brain and spinal cord. TDP-43 dysfunction can lead to deficits in chromatin processing and double-stranded RNA (dsRNA) accumulation, potentially activating the innate immune system and promoting neuroinflammation. We used immunostaining to investigate dsRNA accumulation and other signs of CNS pathology in the spinal cords of amiR-TDP-43 mice and found data supporting the notion that loss of TDP-43 function could contribute to neuropathology by increasing dsRNA deposition and subsequent innate immune system activation.

(Cerebral Cortex, 2023)

In this study, we use a combination of histology, immunostaining, and genetics to characterize cell-type-specific expression of AKT isoforms in human and mouse brains. In mice, we find that AKT1 is the most broadly expressed isoform, with expression in excitatory neurons and the sole detectable AKT isoform in gamma-aminobutyric acid ergic interneurons and microglia. By contrast, we find that AKT2 is the sole isoform expressed in astroglia and is not detected in other neural cell types. Because AKT signaling is linked to numerous neurological disorders, a greater understanding of cell-specific isoform expression could improve treatment strategies involving AKT.

(Cerebral Cortex Communications, 2021)

Our studies revealed AKT isoform- and sex-specific effects on anxiety, spatial and contextual memory, and fear extinction. These results highlight sex as a biological variable and isoform- or cell type-specific AKT signaling as potential targets for improving treatment of neuropsychiatric disorders.

(eLife, 2020)

In this study, sleep and electroencephalography (EEG) oscillations were recorded from aged Dp(16)1Yey/+ mice (Dp16), a mouse model of DS. We observed disrupted sleep demonstrated by increased activity during the dark phase and increased time awake at the expense of NREM sleep compared to wild-type mice. These results in Dp16 mice are consistent with sleep disturbances found in individuals with DS, and the abnormal EEG oscillations in aged Dp16 mice suggest a potential role for GABAergic activity in these sleep and EEG abnormalities.

(Neuroscience, 2018)