SEC FORM 3

SEC Form 3

FORM 3

UNITED STATES SECURITIES AND EXCHANGE COMMISSION
Washington, D.C. 20549

INITIAL STATEMENT OF BENEFICIAL OWNERSHIP OF SECURITIES

Filed pursuant to Section 16(a) of the Securities Exchange Act of 1934
or Section 30(h) of the Investment Company Act of 1940

OMB APPROVAL

OMB Number:			3235-0104
Estimated average burden
hours per response:			0.5

1. Name and Address of Reporting Person^*

MAYFIELD X LP /DE

(Last)

(First)

(Middle)

2800 SAND HILL ROAD

SUITE 250

(Street)

MENLO PARK

94025

(City)

(State)

(Zip)

2. Date of Event Requiring Statement (Month/Day/Year)
05/04/2006

3. Issuer Name and Ticker or Trading Symbol
Northstar Neuroscience, Inc. [ NSTR ]

4. Relationship of Reporting Person(s) to Issuer
(Check all applicable)

Director	X	10% Owner
Officer (give title below)		Other (specify below)

5. If Amendment, Date of Original Filed (Month/Day/Year)

6. Individual or Joint/Group Filing (Check Applicable Line)

	Form filed by One Reporting Person
X	Form filed by More than One Reporting Person

Table I - Non-Derivative Securities Beneficially Owned
1. Title of Security (Instr. 4)	2. Amount of Securities Beneficially Owned (Instr. 4)	3. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	4. Nature of Indirect Beneficial Ownership (Instr. 5)
Common Stock	72,500	D⁽¹⁾⁽²⁾⁽⁴⁾
Common Stock	2,500	I⁽¹⁾⁽³⁾⁽⁴⁾	by MF AIV
Common Stock	8,333	I⁽¹⁾⁽²⁾⁽⁴⁾	by MPF

Table II - Derivative Securities Beneficially Owned (e.g., puts, calls, warrants, options, convertible securities)
1. Title of Derivative Security (Instr. 4)	2. Date Exercisable and Expiration Date (Month/Day/Year)		3. Title and Amount of Securities Underlying Derivative Security (Instr. 4)		4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
1. Title of Derivative Security (Instr. 4)	Date Exercisable	Expiration Date	Title	Amount or Number of Shares	4. Conversion or Exercise Price of Derivative Security	5. Ownership Form: Direct (D) or Indirect (I) (Instr. 5)	6. Nature of Indirect Beneficial Ownership (Instr. 5)
Series A Convertible Preferred Stock	⁽⁵⁾	⁽⁵⁾	Common Stock	1,740,000	$0	D⁽¹⁾⁽²⁾⁽⁴⁾
Series B Convertible Preferred Stock	⁽⁵⁾	⁽⁵⁾	Common Stock	517,856	$0	D⁽¹⁾⁽²⁾⁽⁴⁾
Series C Convertible Preferred Stock	⁽⁵⁾	⁽⁵⁾	Common Stock	280,562	$0	D⁽¹⁾⁽²⁾⁽⁴⁾
Series D Convertible Preferred Stock	⁽⁵⁾	⁽⁵⁾	Common Stock	435,000	$0	I⁽¹⁾⁽²⁾⁽⁴⁾	by MF X Annex
Series A Convertible Preferred Stock	⁽⁵⁾	⁽⁵⁾	Common Stock	60,000	$0	I⁽¹⁾⁽³⁾⁽⁴⁾	by MF AIV
Series B Convertible Preferred Stock	⁽⁵⁾	⁽⁵⁾	Common Stock	17,857	$0	I⁽¹⁾⁽³⁾⁽⁴⁾	by MF AIV
Series C Convertible Preferred Stock	⁽⁵⁾	⁽⁵⁾	Common Stock	9,675	$0	I⁽¹⁾⁽³⁾⁽⁴⁾	by MF AIV
Series D Convertible Preferred Stock	⁽⁵⁾	⁽⁵⁾	Common Stock	30,000	$0	I⁽¹⁾⁽³⁾⁽⁴⁾	by MF AIV
Series A Convertible Preferred Stock	⁽⁵⁾	⁽⁵⁾	Common Stock	200,000	$0	I⁽¹⁾⁽²⁾⁽⁴⁾	by MPF
Series B Convertible Preferred Stock	⁽⁵⁾	⁽⁵⁾	Common Stock	59,524	$0	I⁽¹⁾⁽²⁾⁽⁴⁾	by MPF
Series C Convertible Preferred Stock	⁽⁵⁾	⁽⁵⁾	Common Stock	32,248	$0	I⁽¹⁾⁽²⁾⁽⁴⁾	by MPF
Series D Convertible Preferred Stock	⁽⁵⁾	⁽⁵⁾	Common Stock	35,000	$0	I⁽¹⁾⁽²⁾⁽⁴⁾	by MPF

1. Name and Address of Reporting Person^*

MAYFIELD X LP /DE

(Last)

(First)

(Middle)

2800 SAND HILL ROAD

SUITE 250

(Street)

MENLO PARK

94025

(City)

(State)

(Zip)

Relationship of Reporting Person(s) to Issuer

Director	X	10% Owner
Officer (give title below)		Other (specify below)

1. Name and Address of Reporting Person^*

Mayfield X Management LLC

(Last)

(First)

(Middle)

2800 SAND HILL ROAD

SUITE 250

(Street)

MENLO PARK

94025

(City)

(State)

(Zip)

Relationship of Reporting Person(s) to Issuer

Director		10% Owner
Officer (give title below)	X	Other (specify below)
		See Explanation of Responses

1. Name and Address of Reporting Person^*

MAYFIELD X ANNEX A DELAWARE LP

(Last)

(First)

(Middle)

2800 SAND HILL ROAD

SUITE 250

(Street)

MENLO PARK

94025

(City)

(State)

(Zip)

Relationship of Reporting Person(s) to Issuer

Director		10% Owner
Officer (give title below)	X	Other (specify below)
		See Explanation of Responses

1. Name and Address of Reporting Person^*

Mayfield X Annex Management LLC

(Last)

(First)

(Middle)

2800 SAND HILL ROAD

SUITE 250

(Street)

MENLO PARK

94025

(City)

(State)

(Zip)

Relationship of Reporting Person(s) to Issuer

Director		10% Owner
Officer (give title below)	X	Other (specify below)
		See Explanation of Responses

1. Name and Address of Reporting Person^*

MAYFIELD IX MANAGEMENT LLC

(Last)

(First)

(Middle)

2800 SAND HILL ROAD

SUITE 250

(Street)

MENLO PARK

94025

(City)

(State)

(Zip)

Relationship of Reporting Person(s) to Issuer

Director		10% Owner
Officer (give title below)	X	Other (specify below)
		See Explanation of Responses

1. Name and Address of Reporting Person^*

MAYFIELD ASSOCIATES FUND IV L P

(Last)

(First)

(Middle)

2800 SAND HILL ROAD

SUITE 250

(Street)

MENLO PARK

94025

(City)

(State)

(Zip)

Relationship of Reporting Person(s) to Issuer

Director		10% Owner
Officer (give title below)	X	Other (specify below)
		See Explanation of Responses

1. Name and Address of Reporting Person^*

Mayfield Principals Fund LLC

(Last)

(First)

(Middle)

2800 SAND HILL ROAD

SUITE 250

(Street)

MENLO PARK

94025

(City)

(State)

(Zip)

Relationship of Reporting Person(s) to Issuer

Director		10% Owner
Officer (give title below)	X	Other (specify below)
		See Explanation of Responses

1. Name and Address of Reporting Person^*

UNGER WILLIAM D

(Last)

(First)

(Middle)

2800 SAND HILL ROAD

SUITE 250

(Street)

MENLO PARK

94025

(City)

(State)

(Zip)

Relationship of Reporting Person(s) to Issuer

Director		10% Owner
Officer (give title below)	X	Other (specify below)
		See Explanation of Responses

1. Name and Address of Reporting Person^*

AUKEN WENDELL G VAN III

(Last)

(First)

(Middle)

2800 SAND HILL ROAD

SUITE 250

(Street)

MENLO PARK

94025

(City)

(State)

(Zip)

Relationship of Reporting Person(s) to Issuer

Director		10% Owner
Officer (give title below)	X	Other (specify below)
		See Explanation of Responses

1. Name and Address of Reporting Person^*

MYERS FRANK G JR

(Last)

(First)

(Middle)

2800 SAND HILL ROAD

SUITE 250

(Street)

MENLO PARK

94025

(City)

(State)

(Zip)

Relationship of Reporting Person(s) to Issuer

Director		10% Owner
Officer (give title below)	X	Other (specify below)
		See Explanation of Responses

Explanation of Responses:

1. The individual filers for this Form 3, along with the entities listed below, include William D. Unger; Wendell G. Van Auken, III; F. Gibson Myers, Jr.; Kevin A. Fong; Yogen K. Dalal; A. Grant Heidrich, III; David J. Ladd; Allen L. Morgan and Robert T. Vasan. Electronic filing limits the number of filers on any one Form 3 to 10. The remainder of the filers are being reported on a separate Form 3.

2. The individual Reporting Persons listed, except for Mr. Myers, are Managing Directors of Mayfield X Management, LLC, which is the sole General Partner of each of Mayfield X (MF X) and Mayfield Principals Fund (MPF). The individual Reporting Persons listed, except for Mr. Myers, are Managing Directors of Mayfield X Annex Management, LLC, which is the sole General Partner of Mayfield X Annex (MF X Annex). Such individual Reporting Persons may be deemed to have shared voting and dispositive power over the shares which are or may be deemed to be beneficially owned by MF X, MF X Annex and MPF, but disclaim such beneficial ownership, except to the extent of their pecuniary interest therein.

3. The individual Reporting Persons listed, except for Mr. Ladd, Mr. Morgan and Mr. Vasan, are Managing Directors of Mayfield IX Management, LLC, which is the sole General Partner of Mayfield Associates Fund IV (MF AIV). Such individual Reporting Persons may be deemed to have shared voting and dispositive power over the shares which are or may be deemed to be beneficially owned by MF AIV, but disclaim such beneficial ownership, except to the extent of their pecuniary interest therein

4. The filing of this statement shall not be deemed an admission that, for the purposes of Section 16 of the Securities Exchange Act of 1934 or otherwise, the Reporting Persons are the beneficial owners of equity securities covered by this statement. Each of the Reporting Persons included in this filing hereby designates Mayfield X as its designated filer of Forms 3, 4 and 5 in accordance with Section 16(a) of the Securities Exchange Act of 1934 and the rules thereunder.

5. The convertible preferred stock is convertible at any time, at the holder's election, on a 2-for-3 basis and has no expiration date.

Remarks:

	James T. Beck, Attorney-In-Fact for each of the Reporting Persons	05/04/2006
	** Signature of Reporting Person	Date
Reminder: Report on a separate line for each class of securities beneficially owned directly or indirectly.
* If the form is filed by more than one reporting person, see Instruction 5 (b)(v).
** Intentional misstatements or omissions of facts constitute Federal Criminal Violations See 18 U.S.C. 1001 and 15 U.S.C. 78ff(a).
Note: File three copies of this Form, one of which must be manually signed. If space is insufficient, see Instruction 6 for procedure.
Persons who respond to the collection of information contained in this form are not required to respond unless the form displays a currently valid OMB Number.