Some people with psychiatric conditions, including addiction and attention deficit hyperactivity disorder, struggle to control their urges or make decisions under uncertainty. In a collaboration between the University of Cambridge and the University of British Columbia, Tristan Hynes and colleagues used rats to explore the role of a specific reward-related neuron population in shaping impulsivity and risky decision-making during a gambling task.
As reported in their JNeurosci paper, the researchers manipulated the neuron population's activity as rats chose between four holes associated with different probabilities of receiving a reward or a time-out punishment. Influencing neuron activity as rats learned the task affected risky decision-making differently in males and females. But when the researchers manipulated neuron activity after the rats had already learned the task, this selectively affected motor impulsivity in both sexes. In other words, the same neural circuit drove entirely different aspects of behavior depending on timing and sex.
Says Hynes, "These findings underscore that neural circuits don't operate in isolation or uniformly across individuals; they shift their influence depending on sex and experience. So, a one-size-fits-all approach to pharmacotherapy won't cut it: both where someone is in the progression of their disorder and their biological sex can change how the underlying brain circuitry responds to treatment."
