The Brain on LSD

By Raniya Adeel

LSD (lysergic acid diethylamide) is a rather powerful hallucinogenic substance that has captivated neuroscientists for decades due to its profound influence upon the intricate machinery that is the human nervous system.

When first ingested, this compound will primarily target the serotonin receptors within the brain, there’s also serotonin, a neurotransmitter which is responsible for regulating mood and other vital functions. Remarkably, what distinguishes LSD from all other hallucinogens is its molecular architecture, which bears a striking resemblance to serotonin, allowing it to bind tightly to the serotonin receptors. This interaction results in a surge of serotonin-like effects, which can then lead to altered perceptions, emotions and sensory experiences. 

One significant aspect of LSD impact on the nervous system is its disruption of the normal communication between different regions of the brain. Essentially, it dismantles the brain ability to filter and process sensory information, causing an overwhelming influx of unfiltered data. This phenomenon is what underlies the vivid and frequently distorted visual and auditory hallucinations reported by many users of this hallucinogenic. 

Furthermore, LSD has a rather notable influence on what neuroscientists call the default mode network (DMN). This network consists of specific brain regions responsible for self-referential thoughts as well as our sense of self and under typical circumstances, the default mode network would maintain a consistent level of activity that contributes to our everyday sense of identity. However, when under the strange influence of this hallucinogenic, this network will lose its coherence, often leading to a dissolution of the boundaries between one self, including the individual’s relationship with the external environment — a phenomenon often described as "ego dissolution."

Intriguingly, neuroscientists have also observed that LSD has the ability to enhance connectivity between brain regions, ones which wouldn’t typically communicate extensively together without the influence of the hallucinogenic. There’s evidence that suggests it may be able to promote neuroplasticity, the brain’s ability to reorganise and form new connections, and this increased connectivity may play a role in the enhanced creativity that are reported by some people during LSD experiences. However, it’s important to emphasise that the effects of LSD on the nervous system are heavily dependent on the dosage, so while some users may recount these profound and potentially therapeutic experiences, others may encounter more adverse reactions, such as anxiety and paranoia. 

In conclusion, LSD influence on the nervous system involves the modulation of serotonin receptors, alterations in sensory processing, the disruption of the default mode network, and also increased connectivity between brain regions. Although this compound may offer some captivating glimpse into the brain potential for altered states of consciousness, its effects still remain a subject of rigorous research, curiosity and debate within the scientific community.