Intracellular Recording In Vivo and Patch-Clamp Recording on Brain Slices - Animal Models of Acute Neurological Injuries: Injury and Mechanistic Assessments - page 100

regarding population neuronal activity (i.e., fi eld potential recording)
or single neuronal fi ring (i.e., single-unit recording) as described in
the chapter 6. However, the cell type from which the recordings are
made cannot be determined. Furthermore, when neurons cease to
fi re, which is the case after neurological insults such as ischemia,
extracellular recording fails to provide any information about the
spontaneous activities. Conversely, intracellular recording tech-
niques in vivo can provide information on synaptic activities, as
well as membrane properties of individual neurons. More impor-
tantly, in vivo intracellular recording preparation preserves the
neuronal responses in a whole animal preparation as compared to
the brain slice preparation (see below). Combining pharmacological
manipulations, this technique could provide a lot of information
on synaptic transmission and intrinsic membrane property changes
after neurological injuries. At the end of the experiment, the
recorded neurons could be identifi ed by delivery of dyes, such as
HRP ( 5 ), Lucifer yellow ( 6 ), or biocytin ( 7 ), through the recording
pipette. Therefore, intracellular recording and staining in vivo can
collect the electrophysiological and morphological information of
the same neuron from intact animals ( 8 ).

1.2. Materials

1. Electrophysiological equipment.
2. Amplifi er:
Amplifi er is the key component of the electrophysiological
experiments. Many excellent amplifi ers are available in the
market for intracellular recording experiments, e.g., VF-180,
Biologic; Model 1800, A-M System; MCE100C, Biopac, etc.
The one we have been using is AxoClamp 2B from Axon
Instrument [Fig. 1 (1)] with HS-2A headstage. This amplifi er
has the capability for microelectrode current and voltage clamp
recordings.

3. Oscilloscope:
Oscilloscope is used to constantly monitor the electrical signals
collected by the recording electrode and amplifi ed by the
amplifi er for the experimenter to decide the next action during
an experiment. Despite the fact that many researchers just use
the computer monitor to watch the recorded traces, it is desir-
able to have an oscilloscope to check the bridge balance, capacity
compensation, neuronal responses, etc. before collecting the data.
We have been used oscilloscope manufactured by Hitachi
(Tokyo, Japan) [V-555, Fig. 1 (2)] and Tektronix. In addition,
an audio system could be used to monitor the membrane
potential changes, e.g., action potential fi ring [Fig. 1 (8)].
4. Pulse generator and stimulator:
Pulse generator is used to generate commending signals to
synchronize all the equipment to work at the same pace.
We use Master 8 from AMPI Instruments LTD. [Fig. 1 (3)].