In spinal anaesthesia the drug is deposited between:
Dura and arachnoid
Pia and arachnoid
Dura and veebra
Into the cord substance
Local anesthetic is injected into sub arachnoid space between L2-3or L3-4 below the lower end of spinal cord. The drug acts on nerve roots. From padmaja 4th edition Page no 205
Anesthesia