Cell to Cell Communication
Importance
• Studies of cell signaling are helping to answer
some of the most important questions in
biology and medicine – in areas ranging from
embryological development to hormone
action to the development of cancer and
other kinds of disease.
• The signals received by cells, whether
originating from another cell or from some
change in the organism's physical
surroundings, take various forms.
• Cells can sense and respond to
electromagnetic signals, such as light, and to
mechanical signals, such as touch.
• However, cells most often communicate with
each other using chemical signals.
Localized cell to cell communicating
• Some chemical messengers
travel only short distances.
• Local Regulators:
• Substances that influences
cells in the vicinity. E.g.
animal growth factors,
which are compounds that
stimulate nearby target cells
to grow and multiply.
• Local signaling in animals is
called paracrine signaling.
• Another specialized
type of local signaling
occurs between nerve
cells. One nerve cell
produces a
neurotransmitter, that
diffuses (across a
synapse) to a single
target cell that is
touching the first cell.
Long Distance communication
• Both animals and plants
use chemicals called
hormones for signaling at
greater distances.
• The hormone is released
from the source cell into
the blood stream and
travels to the targeted
cells.
Three Stages of cell signaling
• From the perspective of the cell receiving the
message, cell signaling can be divided into
three stages:
1. Signal reception
2. Signal transduction
3. Cellular response
• When reception occurs at the plasma membrane,
the transduction stage is usually a pathway of several
steps, with each molecule in the pathway bringing
about a change in the next. The last molecule in the
pathway triggers the cell's response.
• http://www.youtube.com/watch?v=U6uHotlX
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• http://www.youtube.com/watch?v=89W6uAC
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