Neurotransmission is the process by which signaling molecules called neurotransmitters are released by the axon terminal of a neuron (the presynaptic neuron), and bind to and react with the receptors on the dendrites of another neuron.

1. SUBMITTED TO:- SUBMITTED BY:-
DR. SAUMYA DAS SONI KUMARI
ASSOCIATE PROFESSOR M.PHARM (PHARMACOLOGY)
NIET (PHARMACY INSTITUTE) NIET (PHARMACY INSTITUTE)
PROJECT TITLE : NEUROTRANSMISSION

2.  Introduction
 Steps involved in Neurotransmission
 Neurotransmitter of ANS
 Reference

3.  Neurotransmission is the process by which signaling
molecules called neurotransmitters are released by
the axon terminal of a neuron, and bind to and react
with the receptors on the dendrites of another neuron
a short distance away.
 Examples of Neurotransmitter are:-
• Nor-Epinephrine
• Acetylcholine

4. • Impulse conduction
• Transmitter release
• Transmitter action on post synaptic membrane
• Post junctional activity
• Termination of transmitter

5. Reference:- https://ib.bioninja.com.au/standard-level/topic-6-human-
physiology/65-neurons-and-synapses/synaptic-transfer.html

6.  The resting membrane potential (-70 mV negative
inside) is established by high K+ permeability of
axonal membrane and high axoplasmic concentration
of this ion coupled with low Na+ permeability.
 Stimulation or arrival of an electrical impulse causes a
sudden increase in Na+ conductance leads to
depolarization (reverse polarization: MP becoming 20
mV positive)

7.  K+ ions then move out in the direction of their concentration
gradient and repolarization is achieved.• The ionic distribution
is normalized during the refractory period by the activation of
Na+ K+ pump.
 The action potential (AP) thus generated activate ionic
channels at the next excitable part of the membrane and the AP
is propagated without decrement.

8.  The transmitter (excitatory or inhibitory) is stored in
prejunctional nerve endings within 'synaptic vesicles'•
Nerve impulse promotes fusion of vesicular and axonal
membranes through Ca2 entry which fluidizes
membranes.
 All contents of the vesicle (transmitter, enzymes and
other proteins) are released in the junctional cleft.

9. • The released transmitter combines with specific
receptors on the postjunctional membrane• Depending on
its nature induces an excitatory postsynaptic potential
(EPSP) or an inhibitory postsynaptic potential (IPSP)
• EPSP Increases permeability to cations Na+ orCa2+
influx causes depolarization followed by K+ efflux.
• IPSP Increase in permeability to anions CI ions move
in tend to hyperpolarize the membrane.

10.  Stabilization of the membrane or hyperpolarization
can also result from selective increase in permeability
to K+ ions, which move out carrying +ve charges.

11.  EPS generates a propagated post junctional AP which
results in Nerve impulse (in neuron) Contraction (in
muscle) or secretion (in gland).
 An IPSP stabilizes the postjunctional membrane and
resists depolarizing stimuli.

12.  The various mechanisms of termination of transmitter
action are,• Following its combination with the
receptor, the transmitter is locally degraded (e.g. ACh)•
 Is partly taken back into the prejunctional neuron by
active reuptake and partly diffuses away (e.g. NA).

13. Reference:- https://slideplayer.com/slide/5838498/

14. Reference:-https://www.slideshare.net/waliwalikhan/acetylcholine-
74143163

15.  Tripathi K.D 'Essentials of medical pharmacology' 6th
edition, Jaypee Brothers Medical Publications (P) Ltd.
New Delhi, 2006Page No. 89-92.
 Goodman & Gilman' 'The Pharmacological basis of
Therapeutics' 11t edition Page No.145-150.
 https://www.slideshare.net/waliwalikhan/acetylcholine-
74143163