Final answer:
Antipsychotic medications function by chiefly antagonizing the D2 dopamine receptor, which is integral to treating psychotic symptoms like those in schizophrenia.
Step-by-step explanation:
Antipsychotics exert their function primarily by antagonising the D2 receptor. Drugs such as risperidone (Risperdal) are known to antagonize D2 along with serotonin type 2 receptors. They also have affinities for other receptors such as adrenergic and histaminergic H1 receptors. The D2 receptor is a subtype of the dopamine receptor that is linked to the treatment of symptoms associated with conditions like schizophrenia, which has been associated with overactive dopamine neurotransmission. Therefore, by blocking the dopamine's effects at the D2 receptor, antipsychotic medications help in reducing psychotic symptoms such as hallucinations and delusions by preventing dopamine from signaling information to adjacent neurons.