1. By-AAYUPTA MOHANTY
GROUP 5

2. EXTIRPATION METHOD- The
extirpation method attempts to determine
the function of a given part of the brain by
removing or destroying it and observing
the resulting changes in the animal's
behavior A method for extirpation of the
pineal gland in albino rats and other
rodents (e. g., ground squirrels) is
proposed. Epiphysectomy is carried out by
resection of a fragment of the bone with the
underlying pineal gland. Using this
method, many animals can be operated
within a short period; the method is
reliable and simple, which recommends it
for chronobiological studies.

. Pierre Flourens (1794-1867) was a professor of natural history at the College de France in Paris,
who systematically destroyed parts of the brain and spinal cord in pigeons and observed the
consequences of doing so. Flourens concluded that the cerebrum controls higher mental
processes, parts of the midbrain control visual and auditory reflexes, the cerebellum controls
coordination, and the medulla governs heartbeat, respiration, and other vital functions.
Marshall Hall (1790-1857) Focused more on different parts of the brain and nervous system. He
postulated that voluntary moveThe extirpation method attempts to determine the function of a
given part of the brain by removing or destroying it and observing the resulting changes in the
animal's behaviorment depends on the cerebrum, reflex movement on the spinal cord,
involuntary movement on direct stimulation of the muscles, and respiratory movement on the
medulla

3. Section of various parts of CNS where extirpation can be done-
1.SPINAL LEVEL-at the level of upper segments of spinal cord.
2.BULBAR LEVEL-between Medulla Oblongata and Mesencephalon.
3.MESENCEPHALIC LEVEL-section between mid brain and hind brain.
4.DIENCEPHALIC LEVEL-section above diencephalon.
Local Damage-
1.Mechanical-Pricking with a needle or scalpel.
2.ELECTRICAL-Inserting thin electrodes into the brain through which direct
current is passed and produces destruction of tissues.
3.FREEZING OR THERMAL COAGULATION
4.INTENSE X RAY OR ULTRASONIC VIBRATION-portions of brain tissue can
be damaged.nerve pathways can be damaged by vibrations of intensity that does
not effect the nerve cells.

4. 5.PROTON RADIATION
-Non-invasive.
inserts electrodes.
does not destroy skin or bones.
apparatus is applied on some
portions of brain.

5. Stimulation-
Electrical stimulation-applying a weak electrical
stimulation to definite parts of CNS to produce
different motor reactions.
Used in neurosurgical operations on humans.
Employed to examine the functions of brain stem and
spinal cord.
For this purpose,electrodes are implanted in different
brain structures and attached to cranial bones.
Non-invasive technique known as transcranial direct
current stimulation (TDCS).
TDCS involves stimulating specific regions of the brain
with low-level electrical currents to enhance or reduce
the activity of neurons. Over the last decade, the
procedure has shown promise at improving brain
. functioning in stroke victims as well as in people
withParkinson's disease. But this is the first study to
show that TDCS can help healthy individuals do better
on math tests.

6. Chemical brain stimulation is the application of chemicals to brain tissue in order
to study aspects of neurochemistry , neuroanatomy andneurophysiology.
Intoduction of different chemicals stimulate different parts of CNS.
Uses the technique of electrophoresis.
A small micro pipette filled with solution is introduced into nerve centres.one small
electrode is inserted into mico pipette.another electrode is applied to the surface o
the body.when a weak DC is passed through the electrodes,the solution from the
pipette is introduced into the tissue.
Electrophysiology is the study of the electrical
properties of biological cells and tissues.
It involves measurements of voltage change or electric
current on a wide variety of scales from single ion
channel proteins to whole organs like the heart.
In neuroscience, it includes measurements of the
electrical activity of neurons, and particularly action
potential activity.
Recordings of large-scale electric signals from the
nervous system.
Used in acute and chronic expts and neurosurgical
operations.

7. Stereotactic surgery or stereotaxy is
a minimally invasive form
of surgical intervention which makes use
of a three-dimensional coordinates system
to locate small targets inside the body and
to perform on them some action such
as ablation (removal),biopsy, lesion,
injection, stimulation,
implantation, radiosurgery (SRS) etc.
its applications have been limited to brain surgery
The Horsley–Clarke apparatus they
developed was used for animal
experimentation and implemented
a Cartesian (three-orthogonal axis)
system. Improved designs of their original
device came into use in the 1930s for
animal experimentation and are still in
wide use today in all
animal neuroscience laboratories

8. Electroencephalography-EEG refers to the recording of the brain's spontaneous
electrical activity over a short period of time, usually 20–40 minutes, as recorded
from multiple electrodes placed on the scalp.
In neurology, the main diagnostic application
of EEG is in the case of epilepsy, as epileptic
activity can create clear abnormalities on a
standard EEG study.[3]
A secondary clinical use of EEG is in the
diagnosis of coma, encephalopathies,
and brain death.
EEG used to be a first-line method for the
diagnosis of tumors, stroke and other focal
brain disorders, but this use has decreased
with the advent of anatomical imaging
techniques such as MRI and CT.

9. Wave patterns
delta waves.
Delta is the frequency range up to 4 Hz. It tends to be
the highest in amplitude and the slowest waves. It is
seen normally in adults in deep sleep. It is also seen
normally in babies. It may occur focally with subcortical
lesions and in general distribution with diffuse lesions,
metabolic encephalopathy hydrocephalus or deep
midline lesions. It is usually most prominent frontally in
adults (e.g. FIRDA - Frontal Intermittent Rhythmic
Delta) and posteriorly in children (e.g. OIRDA -
Occipital Intermittent Rhythmic Delta).
theta waves.
Theta is the frequency range from 4 Hz to 7 Hz. Theta is
seen normally in young children. It may be seen in
drowsiness or arousal in older children and adults; it
can also be seen in meditation.[17] Excess theta for age
represents abnormal activity. It can be seen as a focal
disturbance in focal subcortical lesions; it can be seen in
generalized distribution in diffuse disorder or metabolic
encephalopathy or deep midline disorders or some
instances of hydrocephalus. On the contrary this range
has been associated with reports of relaxed, meditative,
and creative states.

10. Alpha is the frequency range from 8 Hz to 12 Hz. Hans Berger named the first
rhythmic EEG activity he saw as the "alpha wave". This was the "posterior basic
rhythm" (also called the "posterior dominant rhythm" or the "posterior alpha
rhythm"), seen in the posterior regions of the head on both sides, higher in amplitude
on the dominant side. It emerges with closing of the eyes and with relaxation, and
attenuates with eye opening or mental exertion. The posterior basic rhythm is
actually slower than 8 Hz in young children (therefore technically in the theta range).
beta waves.
Beta is the frequency range from 12 Hz to about 30 Hz. It is seen usually on both
sides in symmetrical distribution and is most evident frontally. Beta activity is closely
linked to motor behavior and is generally attenuated during active
movements.[20] Low amplitude beta with multiple and varying frequencies is often
associated with active, busy or anxious thinking and active concentration. Rhythmic
beta with a dominant set of frequencies is associated with various pathologies and
drug effects, especially benzodiazepines. It may be absent or reduced in areas of
cortical damage. It is the dominant rhythm in patients who are alert or anxious or
who have their eyes open.
gamma waves.
Gamma is the frequency range approximately 30–100 Hz. Gamma rhythms are
thought to represent binding of different populations of neurons together into a
network for the purpose of carrying out a certain cognitive or motor function.[2]