D1 receptors regulate dendritic morphology in normal and stressed prelimbic cortex.

Area of Science:

• Neuroscience
• Stress Research
• Dopamine Signaling

Background:

• Stress and prefrontal cortex dysfunction are linked to psychological disorders.
• Medial prefrontal cortex (mPFC) structure and function are altered by stress.
• Chronic stress induces dendritic retraction in the prelimbic region (PL) of the mPFC.

Purpose of the Study:

• To investigate the role of dopamine D1 receptor (D1R) signaling in stress-induced dendritic remodeling in the PL of the mPFC.
• To determine if D1R blockade during stress prevents dendritic retraction and to assess the effect of D1R blockade in unstressed conditions.

Main Methods:

• Rats were subjected to daily restraint stress for 10 days.
• Dopamine D1 receptor antagonist SCH23390 or vehicle was infused into the PL region.
• Dendritic morphology of pyramidal neurons in the PL was analyzed using Golgi histology.

Main Results:

• Stressed rats receiving vehicle showed significant dendritic retraction in the PL compared to unstressed controls.
• D1R blockade in the PL prevented stress-induced dendritic retraction.
• D1R blockade in unstressed rats also led to dendritic retraction, indicating a role in maintaining normal morphology.

Conclusions:

• Dopaminergic transmission via D1R in the mPFC directly mediates stress-induced retraction of apical dendrites.
• Dopamine signaling is crucial for maintaining normal dendritic morphology in the absence of stress.
• These findings elucidate the specific mechanisms of stress-induced neural plasticity in the mPFC.