Dopamine System Dysregulation in Schizophrenia Pathophysiology

Schizophrenia is characterised by an imbalance in dopamine signalling, with excessive dopaminergic transmission in subcortical regions and reduced tone in prefrontal circuits. This dysregulation underlies the emergence of positive symptoms—such as hallucinations and delusions—through aberrant salience attribution, while cognitive and negative symptoms reflect disrupted prefrontal dopamine modulation. Upstream of midbrain dopamine neurons, impaired inhibitory control by hippocampal and cortical GABAergic interneurons leads to hippocampal hyperactivity, which in turn drives excessive firing of ventral tegmental area (VTA) cells. Stress and developmental insults compound this circuitry disturbance, precipitating a persistent shift in excitation–inhibition balance. An improved mechanistic understanding of these interconnected nodes has spurred investigations into novel circuit‐based interventions that extend beyond direct dopamine‐receptor antagonism.

Research from Nature Portfolio

Recent studies have demonstrated that restoring glutamatergic co‐agonism can recalibrate inhibitory circuits and indirectly normalise dopamine neuron activity. In a neurodevelopmental mouse model, administration of D‐serine rescued both synaptic and intrinsic inhibitory control of cortical pyramidal neurons by enhancing the excitability of parvalbumin‐positive interneurons and activating small‐conductance Ca2+‐activated K+ channels, thereby improving cognitive performance and rebalancing downstream dopaminergic output. Complementary work has shown that selective overexpression of extrasynaptic α5‐GABAA receptors in the ventral hippocampus reverses hippocampal hyperactivity and corrects aberrant VTA firing. Chemogenetic dissection of discrete projections revealed that modulation of the hippocampus–nucleus accumbens pathway normalises dopamine neuron activity, while targeting the hippocampus–prefrontal cortex projection preferentially restores cognitive flexibility, underscoring the therapeutic potential of circuit‐specific strategies.

Dopamine System Dysregulation in Schizophrenia Pathophysiology publication trend

The graph below shows the total number of articles in dopamine system dysregulation in schizophrenia pathophysiology across all publications each year (not limited to Nature Index journals).

Technical terms

Dopaminergic transmission: Neural signalling mediated by the neurotransmitter dopamine, crucial for reward and salience processing.

Ventral tegmental area (VTA): A midbrain region containing dopamine neurons that project to limbic and cortical targets.

Parvalbumin‐positive interneurons: Fast‐spiking GABAergic cells that regulate the timing and synchrony of principal neuron firing.

Aberrant salience: The inappropriate assignment of importance to neutral stimuli, central to the formation of psychotic symptoms.

Synaptic plasticity: The capacity of synapses to strengthen or weaken over time, underpinning learning and adaptation.

Excitation–inhibition balance: The equilibrium between excitatory and inhibitory neural activity necessary for stable circuit function.

References

1. Dysregulation of Midbrain Dopamine System and the Pathophysiology of Schizophrenia. Frontiers in Psychiatry (2020).
2. Hippocampal Hyperactivity as a Druggable Circuit-Level Origin of Aberrant Salience in Schizophrenia. Frontiers in Pharmacology (2020).
3. D-serine reconstitutes synaptic and intrinsic inhibitory control of pyramidal neurons in a neurodevelopmental mouse model for schizophrenia. Nature Communications (2023).
4. Modulation of extrasynaptic GABAA alpha 5 receptors in the ventral hippocampus normalizes physiological and behavioral deficits in a circuit specific manner. Nature Communications (2019).
5. Beyond Dopamine Receptor Antagonism: New Targets for Schizophrenia Treatment and Prevention. International Journal of Molecular Sciences (2021).