Prenatal stress causes gender-dependent neuronal loss and oxidative stress in rat hippocampus

Area of Science:

• Neuroscience
• Developmental Biology
• Toxicology

Background:

• Prenatal stress is a known environmental factor impacting offspring neurodevelopment.
• Oxidative stress plays a role in various neurological disorders.
• The hippocampus is crucial for learning and memory and is vulnerable to stress.

Purpose of the Study:

• To investigate the impact of prenatal stress on hippocampal neuronal changes in female and male rat offspring.
• To explore the role of oxidative stress in mediating these prenatal stress-induced effects.

Main Methods:

• Pregnant rats were subjected to restraint stress during middle (MS) or later (LS) stages of gestation.
• One-month-old offspring were assessed for hippocampal neuron number and neuronal nitric oxide synthase (nNOS) expression.
• Calcium content and oxidant generation were measured in the hippocampal CA3 region of female offspring.

Main Results:

• Both MS and LS increased nNOS-positive neurons in the hippocampus of both sexes.
• MS and LS significantly decreased hippocampal neuron numbers in female offspring, but not males.
• LS exposure led to increased calcium and oxidant generation in the female offspring hippocampus.

Conclusions:

• Prenatal stress can induce oxidative stress in the developing hippocampus.
• This oxidative stress contributes to neuronal damage and loss, particularly in female offspring.
• These findings highlight the long-term neurodevelopmental consequences of prenatal stress.