Intracerebral viral injection is a technique for delivering viral vectors into specific brain regions to study gene expression, neurodegeneration, or circuit manipulation.

Dorsal root ganglion (DRG) injection is a technique used to deliver drugs, viral vectors, or tracers directly into the DRG for studying sensory neurons.

Spinal cord injection involves precise needle insertion into the intrathecal or epidural space under anesthesia to deliver drugs, viral vectors, or cells directly to the central nervous system.

An intradermal injection is administered into the dermis, the layer just beneath the epidermis, using a small-gauge needle at a shallow angle (10–15°).

Hepatic portal vein (HPV) injection is a method used to deliver substances directly into the liver via the portal circulation.

Intraperitoneal (IP) injection is a method for administering drugs, vaccines, or biological agents into the peritoneal cavity.