Keywords

Diphenhydramine; Neuroscience; Cellular Biology; Development; Neuro-2a; Drug Exposure

Abstract

Anticholinergic medications, such as diphenhydramine (commonly known as Benadryl), are increasingly recognized for their association with cognitive impairment and neurodegenerative disease. These medications, which inhibit the action of acetylcholine, a neurotransmitter essential for the formation and utilization of the central and peripheral nervous system, have been implicated in conditions such as dementia and may impact fundamental cellular processes like neurogenesis and cell proliferation. This study investigates the effects of diphenhydramine on neurogenesis when introduced to Neuro-2a cells during differentiation. For all studies cells were plated on coverslips or in 6-well plates with differentiation media containing 0 ng/mL, 50 ng/mL, or 100 ng/mL of diphenhydramine. Immunofluorescence staining was utilized to assess morphological alteration via projection length and cell diameter. MTS assays determined cellular metabolic activity/proliferation. For protein expression, western blotting was used to quantify Tau-5, Vesicle Acetylcholine Transporter, and amyloid-beta protein levels.  Acetylcholine assays were utilized to determine acetylcholine activity across these same treatment groups. Results from this study suggest that diphenhydramine impairs projection growth and differentiation at both 50 ng/mL and 100 ng/mL, with distinct disruption at 50 ng/mL. These results provide key insights into the dose-dependent mechanism underlying anticholinergic neurotoxicity, with implications for drug safety and therapeutic development. Future research will explore pathways involved in diphenhydramine induced neurotoxicity by utilizing RT-qPCR and investigate its effect in vivo.

Thesis Completion Year

2026

Thesis Completion Semester

Spring

Thesis Chair

Borgon, Robert

College

College of Medicine

Department

Burnett School of Biomedical Sciences

Thesis Discipline

Molecular Neurobiology

Language

English

Access Status

Open Access

Length of Campus Access

None

Campus Location

Orlando (Main) Campus

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