Brain Mind Behavior MDMAs and PTSD

What is psychedelic?

A class of drugs that cause sensory changes, such as auditory or visual.

What receptors do MDMAs impact?

They agonize exclusively serotonin receptors

What is an empathogen?

A compound that increases feelings of empathy and connectedness.

What receptors do empathogens effect?

serotonin, norepinephrine, and dopamine

What is the current treatment for PTSD?

CBT or exposure therapy, paired with anti-depressants or anti-anxiety medication.

What does MDMA do to improve PTSD symptoms?

MDMA reopens the critical period for the brain for a few weeks, allowing the patient to change brain connections. As a result, they can form new connections to the traumatic scene because of brain plasticity.

What do animal studies allow us to see that human studies don’t?

Animal studies allow us to take the brain out and look at the physical changes that result from MDMA brain plasticity.

What are the symptoms of PTSD?

Presence of intrusion symptoms, such as memories, nightmares, and flashbacks, and persistent avoidance of stimuli associated with the traumatic event. There are also negative laterations in mood or cognition.

What is the mechanism of action for MDMA?

MDMA gains access to the presynaptic neuron through SERT (serotonin transporter). It then blocks serotonin from being packaged into vesicles by blocking VMAT2. There is lots of serotonin in the presynaptic neuron, and MDMA then facilitates the movement of serotonin through SERT into the synapse.

What is plasticity like in postnatal development?

Synapse count is low at birth, it increases at around 2 years, and then decreases after that. The brain structures become increasingly pronounced with age.

What is a critical period?

Time when experience and neural activity that reflects that experience have maximal effect on the acquisition or skilled execution of a particular behavior.

How do critical periods impact learning language?

Language acquisition in humans is easier at younger ages because there is more plasticity. Fluency is that of a native if the language is learned from 3-7 years old. It then decreases after that.

What are the basic properties of critical periods?

Once a critical period ends, the core features of a behavior are largely unaffected by subsequent experience. If not exposed to appropriate stimuli during the critical period, then it is difficult to remedy. Critical periods rely particularly on changes in organization and function of circuits int he cerebral cortex.

What are the effects of visual deprivation?

Visual deprecation in cats cause cortical blindness in kittens, but nothing long-term in an adult cat.

What is cortical blindness?

The total or partial loss of vision in a normal-looking eye